Planeshift is another one of those MMORPG's, except the difference is its free to play, download, etc, and licensed under the GPL (for the most part, art is copyrighted).
http://www.planeshift.it/
Ok I don't know if its the right place to put this but there isn't a gaming forum.
The download is about 250 mb + some automated updates when you start (of about 20 mb). Looks fairly good for an open source project...
Allegedly I think
"This game was made by nvidia employees combined with other people who had nothing better to do with their time"
The part of the post above is taken from another forum post from a local gaming forums.
I personally am yet to try it but I'll be having a good look at this later today if god willing my power comes back on. (curse you mini-tornado)
I can't wait to give it a go