If you want to listen in your car, TuneIn Radio has a Car Mode that gives you big buttons to quickly switch stations while on the go. The only curious feature here is the ability to search -- I'm not sure you want to be typing in search terms while driving.
For those who are a bit more serious about their streaming media, an upgrade to TuneIn Pro ($4.99) might be worthwhile. The Pro version adds some nifty DVR-like features, so you can pause, rewind, and even record live radio. TuneIn Radio keeps all your recordings in a special section so you can listen to recorded favorites later.
Finally, you may notice that some stations are marked "Restricted by Broadcasters," which means they're not available for streaming through TuneIn. What's nice is that if you happen to click on one of these, TuneIn will automatically find and connect you to a similar station, which is often just as good.