Maybe it's just me, but I find it hard to come across free, high quality themes that fit the 240x240 screen on my 700wx.
I've gotten all of my themes from the "square" section on littlethemes.com
http://www.littlethemes.com/type.asp?t=6
However, It would be nice to have more choices.
I didn't read the forum rules (who does?), so i'm not going to post links to any other forums.
Maybe we can get a compilation going?