I got to the "send the user an email" part, and I realized that I need to send the user a name/unlock-code pair. Which means that I've got to generate that code in PHP that can then be verified in the game. It's mostly done. Just some testing. Lots of string-massaging to come up with a reasonably secure code. Thankfully both PHP and ActionScript have pretty good string handling.
It's not the most secure scheme around, but hopefully it'll at least discourage rampant piracy a bit. Since the code-base of the game is in Flash, I'm not gonna bother with the "play for 60 minutes" version that's become the norm. I'm gonna put a level/music/animation-limited version right on the site with a big ad saying "If you like this and want the super-uber-fancy-shmancy version, click the buy-it-now button and it's yours.