this is making me sad....
grooveshark died so I can't do radio for my friends anymore...
I'm not familiar with it, but I'm sure there are plenty of other services now a days.
There can't be anything as easy to use as Grooveshark.
One of the reasons it was so easy and great to use was the same reason it got sued to death:
It let users upload music to the site, without moderating it, and didn't pay a cent in licencing or royalties or anything.