(Updated) Huh. Why didn't anyone else notice this?

Looks like I wasn't the first to find this.  Sharkbaitbobby compiled a build of the Chrome OS version of the browser well before the debs were available for download.  There may have been other people who found this earlier as well.  Regardless, his is the earliest I've seen so far, so I think he deserves a little credit here. :P

http://sites.google.com/site/randomlinuxnerd/
http://sharkbaitbobby.blogspot.com/

Update: He's also created a new blog for Chromium OS browser builds.  He already has a later build than the one I posted.  (Mine was directly from Google, his are modified versions of Chromium.  The source code for the Chrome OS browser has actually been in the Chromium source for a while.)

http://chromium-os.blogspot.com

I'll be posting any more news I find, but for the latest builds, that's the place to go. :P