We've got a couple of leagues with open teams at www.myfootballnow.com
If you haven't checked it out yet, it's a brand new online football management sim. I haven't seen any reference here to it yet, so wanted to post a link and see if it appeals to anyone here. Just announced that you can play for free forever. It's more in the mode of a text sim (you sign players and coaches, and put together a game plan, but the games are simmed by the server overnight). You can then watch your games in a 2-d game viewer. The creators are very responsive to ideas as well. And, hey, it's free, and fun.