download pockettouch off cydia, once installed first thing to do before opening is go to settings and then go into the pockettouch submenu and you can set shaker options and other gestures on how to use the program.
you have the option to swipe the screen with pockettouch open and change tracks from in your pocket, shake the ipod to change the track, shake the iPod to randomly select a new song. also when your iPod is locked you can shake to change tracks.
this program is designed around the iPhone and iPod touch 1st gen and has never been tested on 2nd gen, I couldn't see it now working really.