Squirt check around, in another thread here quite a bit more info was posted about Larry's "patent".
Brandon (FTP) says that he's filed but has not received patent status yet, and that the only true unique thing about Larry's method is that it also asks the purchaser to digitally "sign" by typing in their name under the birthdate (that's my interpretation of what he said, he might've actually meant something different).
Then Danny Cox stepped up and showed a few "prior art" instances of the same type of verification system being used years and years ago, one of them on Danny's own site that can still be seen through the Way Back Machine.
It's very interesting stuff - poke around and find it, and then maybe you'll decide to put your javascript version back up.
