Maybe someone's already made one (besides Adobe Acrobat), but I think it'd be neat to have a nifty program/AppleScript that could apply Digital Signatures to any document. Word, TextEdit, PDFs, etc. A double bonus would be able to apply Adobe Signatures as well.
I ran into this problem where I'd download a PDF form, only to have to print it anyway just so I could sign it.
Not sure how it'd work, though. Maybe I shoulda entered that Dream App contest.