I discovered a nice surprise by playing with multitasking when Pandora was running. Not only does it keep streaming music in the background, it actually hooks into some of the same system services that control the iPod app.
For example, double-click the home button while Pandora is running in the background. (If the device is unlocked, it will bring up the task manager which includes audio controls. If it’s locked, it will bring up the audio HUD on top of the lock screen.) In both cases the audio controls connect to Pandora rather than the built-in iPod app. Similarly play/pause and other buttons on external keyboards will now control Pandora if it’s running.
Out of curiosity I hooked the iPhone up to my car stereo’s iPod integration cable. In this case the steering wheel buttons did not control Pandora.
