Gametable is a great, free tool for roleplaying. If you don't know about it yet check it out at: http://gametable.galactanet.com/
The only problem ive had with it is that most of the material avalable is for the swords and sorcery genre. Well, I like playing Superheroes, so Ive created a bunch of pogs and underlays myself, with a superhero theme and posted them on my website. They can be downloaded free at: http://crusadergame.books.officelive.com/POGS.aspx