We've not been the biggest fans of Microsoft Tag for several reasons — it's another standard that would have be be adopted, it's not widely available, etc. — but you have to admit the advert you see above is compelling. And Tag is built ino Windows Mobile 6.5, so we may see it gain some traction.
This video actually is a spec ad directed by a previous Microsoft collaborator.
I Started Something has got a couple more. Check 'em out.