Here are just a couple of ideas that come to mind, although considering that the last ones weren't used for anything.... maybe the "home page" of bonsaitalk.com, or a newsletter type of email from bonsaitalk.... that would be two options that Matt might want to keep open.
Remember, the author can still publish elsewhere, after the contest.
You aren't giving up your rights, only allowing bonsaiTALK to also use the material if desired.
Joanie