The new Internet radio apps available for iPhone/iPod Touch are among the most popular, highest rated, and most downloaded apps in the new iTunes App Store. We’ll take a look at these apps, explore their differences, and examine what they bring to your iPhone or iPod Touch.

I have always been disappointed that the iPod has never included an AM/FM radio. While it’s true that radios built into MP3 players such as Microsoft’s Zune 2 have never been much in terms of reception, the inclusion of any AM/FM radio provides a few very unique benefits:

1. You can use it to listen to television while on the treadmill at the gym. Many gyms these days have a series of TV’s forward of the cardio machines, which broadcast the different channels’ audio on FM frequencies. (This is one feature which the iPhone/iPod Touch does not address with the new radio apps.)

2. Variety. Once in a while, even the largest MP3 collection can get stale, or you just feel like listening to something new on your favorite radio station.

3. News and Information (especially local). If your train gets delayed, you can tune into a station such as 1010 Wins and often get the lowdown on the MTA situation. Or just get up to speed on the local news of the day, traffic, or weather.

Three new radio apps from the Apple Apps Store add so much utility beyond these listed here, that they are really in a class of their own in terms of adding usability to the iPhone/iPod Touch .

The first thing you should know about these apps is that they do not add actual AM/FM tuning capabilities to the iPhone/iPod Touch . Instead, they use Internet radio stations. In many cases, Internet radio stations are stations that are only broadcast over the internet, and have no actual ‘station’ or AM/FM Transmitter. This includes popular internet stations such as SOMA FM’s Groove Salad (neo-lounge).

There are, however, many traditional AM/FM stations and programs which voluntarily (or involuntarily) are rebroadcast or simulcast over the internet as well. There are both advantages and disadvantages to listening to your favorite local AM/FM station over the iPhone/iPod Touch rather than a traditional tuner:

1. Since the broadcast is digital, traditional reception problems do not apply. It does not matter how far you are from the radio station – it can be next door or on the other side of the world – if you have a working internet connection, it will sound exactly the same wherever you are.

2. It requires a more or less constant connection to the internet. This can be a problem if you are in a car or train with your iPhone, as you will likely travel in and out of cellular data range and/or automatically swap between wifi, edge, and 3g. Because of the nature of a radio stream, there is no way to buffer the signal which you did not receive while in a tunnel, for example. I haven’t tested them thoroughly, but your mileage may vary in how any individual app handles reconnects in such situations. In any case, if you are not moving and have a decent connection this is not a problem.

3. The quality of the audio varies. Internet radio stations do not, by and large, make a lot of money. They have to pay for bandwidth, many have no ad revenue, and the legitimate stations need to pay artist royalties on the music they play to the RIAA. To help keep costs down, Internet radio stations will broadcast in lower bitrate streams. This is not really a problem for talk radio, which can easily be broadcast at 32 kbps and sound just fine – but a lot of music stations broadcast below 128 kbps, which isn’t so great. The threshold at which this affects the enjoyment of any given station for any listener is totally subjective.

The first app we will look at is the one which has the widest spectrum of available stations – NullRiver Tuner ($5.99). You can easily get a taste of what is available on NullRiver Tuner by installing a great free audio player known as Winamp on your computer, then visiting a site called Shoutcast.com. You can use Shoutcast to browse all of the stations available, and clicking on them will launch the station in Winamp (iTunes will also work).

Any station available on Shoutcast is also available on NullRiver’s Tuner program for the iPhone/iPod Touch . However, as I write this, only a subset of available stations are browsable on Tuner, and its search feature for other stations seems to be either broken or severely limited.

You can, however, find the stations you want in Shoutcast, open them in Winamp, and then press ‘ALT-3’ or click ‘File…View File Info’ from the Winamp menu. This will open a dialog box, at the top of which will appear the stream URL for the station you are listening to. In many cases this will be an IP-address url with a nonstandard port - for example, here is the stream URL for the Art Bell Time Capsule Station:

http://209.104.4.230:8400

To open this URL in the NullRiver Tuner for iPhone, click on the ‘Search’ icon on the far right of the bottom toolbar, and then click the ‘Open’ button in the top left of the window. Don’t bother entering a title, this will be filled in automatically – just enter the URL exactly as it appears, including the colon and port number, if any. Tuner will automatically open the stream, list the station name and current program, at which point you can bookmark it.

Some of my favorite bookmarks for Tuner include the previously mentioned Groove Salad, KQED San Francisco (NPR), and the George Noory and Art Bell archives of ‘Coast to Coast’ – a very popular call-in show which features UFO, Bigfoot, and other paranormal stuff, as well as its share of nutcases and schizophrenics. It’s a hoot.

Our next app is AOL Radio (FREE). AOL Radio has a smaller, specific set of stations, but it’s a great set, which includes a much better selection of simulcast traditional radio stations. It also has a button for finding stations local to you, which is a great feature. In addition, many of the radio stations will display the album cover and information for the song which is currently playing, during which you can pull up the album or track in iTunes for purchase – again, just a great feature which leverages the iPhone’s capabilities very well.

Some of my favorites on AOL Radio include 1010 Wins (for local news, traffic, and weather), 104.1 WBCN Boston (which is the station which inspired me to go to broadcasting school and spurred a brief DJ career), K-Rock NYC, WCBS Newsradio 880, and WBZ Boston. The best part of internet radio for me is listening to stations I used to listen to when I lived in other parts of the country.

Finally there is Pandora (FREE), which is a very different type of radio app. Pandora does not have a list of internet or simulcast radio stations. Instead, you create a free account, and create your own personalized stations.

For example, you could pick an artist, such as U2, and call that your ‘U2’ station. Pandora will automatically start playing U2 tracks, as well as other music it deems ‘similar’ to U2 using a surprisingly effective algorithm based on the Music Genome Project. While tracks are playing, you can thumbs up or thumbs down them, and Pandora will use this feedback to further customize your station. Like AOL Radio, Pandora features album art and track information, as well as integration with iTunes Store. It also allows you to bookmark songs and artists.

Although Pandora’s audio quality is probably not on par with your MP3 collection, its still very good. Its so good, in fact, that at parties we have started to simply use Pandora rather than listen to our MP3’s. It combines the best of both worlds – the music you like in your MP3 collection, plus the advantage of radio – being surprised by the DJ – but it’s better than both because of its level of customization, and completely hands-off.

The only downside of Pandora is that, due to licensing issues, you can only skip over 4 songs an hour. When you think about it, that isn’t even a big deal, since it’s the only radio app which allows you to skip over songs at all.

Pandora has been available as a web application for many years. However, it’s interesting how much more usable it is as an iPhone app. It’s probably the #1 app in the app store. As I write this it has well over 2400 reviews averaging 4.5 out of 5 stars, although Apple lists it as 8th most popular (I don’t know how they score apps for this purpose).

Sadly, Pandora might not be around for long. As I mentioned previously, RIAA licensing is taking its toll on free internet radio such as Pandora, and there has been a lot of talk about them pulling the plug. With this in mind, I have no idea why Pandora doesn’t just switch to a paid model, either by subscription or by just charging for apps – I think we can all agree we would rather pay for Pandora than have it disappear completely.

Especially considering that a month or so ago the iPhone had no radio functionality whatsoever, these three apps have been a total game-changer in terms of the iPhone’s capabilities and featureset. Its no wonder they among the most popular apps in the Apps store.

For folks that don’t have a new 3G iPhone and have a Wifi connection, I wanted to recommend a setup I have been using at my bedside for listening to Internet Radio - an iPod Touch with the inexpensive CyberAcoustics Speakers works great and takes up very little space.