Here's a new app that I'm sure will be used and abused by creatives everywhere, Stickybits is both iPhone and Android ready - with it you can stick barcodes to real world objects, and when scanned they unlock photos, vidoes, anything you want that you've attached to that barcode. You could create scavenger hunts, add extra digital stuff to your biz-card, add a digital guestbook to a real world location, attach digital assembly instructions to that plate you just shattered and glued together with a barcode sticker... The possibilities are endless.
I dunno about you, but I'm downloading this app right now. Momma's gonna have some fun.