i'm guessing you could use a shoutcast stream with an auto dj in the cloud or possibly mixlr. edit: since you want voting, i think mixlr.com is what you want,

i'm guessing you could use a shoutcast stream with an auto dj in the cloud or possibly mixlr. edit: since you want voting, i think mixlr.com is what you want, it's $10 per month or free. i know grooveshark has a radio station thing now too.