DoubleTwist works really well on the scroll and is a excellent alternative to the standard media player which comes with android. It is excellent for people who like me have iTunes music that you just wouldn't be able to play on the scroll normally. In a way DoubleTwist is the iTunes for android. Another great feature is airsync, which is synchronising the device over wifi, instead of connecting the device through USB.
The Only problem is that you can't download it from the scrolls market
However downloading onto and SD card is a way around this
See Post: viewtopic.php?f=16&t=46
Besides that its a great app, well recommended!