Just picked it up. As soon as I saw it I knew it was a 720, it has that nice big gap b/w the rear tire and the seatpost indicating those long chainstays. Then I flipped it over and was able to make out the 0 in front of the serial number and I knew I had a winner.

There are no decals anywhere, no headbadge, and the first number of the serial is partially obscured by paint. It looks like a pretty good paint job, not a rattle can. I would have said that it definitely wasn't original, except that evwxxx says that his/her Trek is the same color, so maybe it was original, who knows. I guess the headbadge fell off. If anybody knows of a way to identify tubing w/o taking the fork out let me know.

It's a 22" and too small for me, so it'll get a bit of a cleaning and then either off to eBay or back on Craigslist. Thanks for all your help, I wouldn't have been able to figure it out without the responses on this thread.