Just for Fun: MyDrawings.com

Another communal online drawing space - MyDrawings.com is a virtual 'graffiti wall'. You can add your own and vote on other's work. There's some really nice drawing going on there. Of course, like all public spaces, there are always a few idiots adding mindless drivel, so its not really suitable for kids. (I know, you probably hear worse language at school, but I want to stay on your mom's good side, okay, so stick with safe sites, please!)