Although I didn't get the chance to attend the Mobile World Congress in Barcelona, Spain this year, I've been hearing a lot about various strategic partnerships, tablet announcements and the like. I think, though, the absolute coolest and most innovative thing I've heard come out of the Congress were these Android pins. No joke. DP Venkatesh of mPortal (and a luminary in the DC mobile community) brought these back from Barcelona and had them on his desk.
It's not the pins, per-se, but it's what Google did with them. The way DP describes it, Google gave various pins out at various stations. Each station housed a brand active in Android (brands like CNN, Samsung, etc.). And there were many different styles of pins. That's the key -- it became a competition to collect all of the different types of pins. Pretty genius, and it encouraged everyone to visit all the Android stations and reach out to others in an attempt to "get the one missing from your collection." (DP, if you read this and have any more details to add, I'd love to hear more in the comments section below.)