Off-beat Invitations

I'd love fun invitations to reflect the mood of my wedding.  Here's one that, while it's not quite polished enough for me, is really fun:

I really love how this couple used old-school style Viewfinder invites! They splurged on the invites and mailed boxes of Viewfinders to their guest list. :) I love the interactive nature of the invite above, but it's way too pricey. Another interactive invite that's better for budgeting purposes is the scratcher idea:

And there's the ever-so-cute pop-up cards: