I've tried last.fm and like the social aspect of the program. However, I feel like the Slacker program is more customizable and has better sound quality. Maybe I'm wrong. Give Slacker a listen and tell me what you think vs. last.fm.

Honestly, I don't use anything on Vagalume OTHER than the feature where you type in an artist and it creates a station. That's it. Thus, 'customizable' doesn't really mean anything. As for sound quality, to that I can't speak, as I'm usually listening with the built-in speakers of the Tablet, which are certainly nothing to write home about.