Oh, I've been kind of doing it already, but I'm willing to let you do it. I just don't know how to arrange the tiles--I seem to have the temptation to put the usernames in alphabetical order. ;p I have a few squares from users who haven't posted in this thread, so... When it comes to that time, I can put them in a .zip file for you or something. I'm thinking maybe 7 columns, and however-many rows depending on the contributions, but that would be up to you.
And to everyone who has already contributed, thank you so much. Please help spread the word of the quilt, so we can get more squares.