One thing that I've always wanted to do is bring my internet radio stations with me while on-the-go. 📡
The iPhone will only support 2G (EDGE and GPRS) at launch (not 3G), but is that enough to handle playing DI.FM or even Last.fm over-the-air, without interruptions?
While on a snowboarding trip in New Hampshire this past winter, I had my MacBook streaming internet audio over GPRS (via my tethered cellphone with unlimited cellular-data) in the hotel all night, and didn't run into any issues with quality or choppiness. — But, it may depend on the towers and how nearby they are. We were in a resort area, so the bandwidth capabilities may be greater than that of other, more rural ones… for example, while driving through the middle of nowhere.
It'll be interesting to see if this works well once the software is available for phones.