Actually, was gonna ask a code question, but will include my version so far for you.

Just a simple code question, I got the signature box to check automatically now, but was wondering why the code isn't
$signaturechecked="CHECKED"
(didn't work) instead of what I ended up using, which is
$signaturechecked CHECKED

Here's my text version so far, but hopefully, more will be added to this by other people. Real useful mod, my favorite so far.