There is, but it's crippled. Only the simplest of controls are exposed to Javascript, and the music stops playing when the app closes or the device locks.
Not true. I'm working on a music webapp for iOS and the audio keeps playing if you exit Safari/lock the device. It's actually quite annoying as the only way to stop the music is to open Safari and pause the audio.
Huh. That must have changed since I last tried to play a podcast through Safari. Thanks for the info.