Yeah- SciLor's GrooveMobile is up to AlphaV5 now. Now you can create play lists on your device and save them. You can also retrieve your play lists from Grooveshark as well. Sweet. It doesn't really look like the folks at nanoGroove are interested in development as much as they are the $5.
http://forum.xda-developers.com/showthread.php?t=640954