Come to the Party!

A cool, underground party where the invites are totally personalized: they're fake IDs. You can only get in with a badly-made fake ID. The picture has to match your face, natch, to show the bouncer that you're on the list. Every time there's a new party new IDs go out, dropped at bars and coffee shops to be picked up, mailed to anonymous PO boxes, delivered in company mail and intercepted in the mail room. The IDs feature a quirk that makes them hard to fake and easy to identify (holographic state seals that are actually a smiley-face, for example). The address is the new location of the party, and the birthday is the date of the shindig.

Boom! Ticket and invitation all in one.