I just came across this, as it started sending traffic to Feeding The Puppy...
...it's called Trendsmap, and it lets you look at Twitter Trends by location on a map of the world. Oh yes, yes indeedy...
...then if you click on one of the words hovering over the area you're looking at, it will bring up the box on the left with the most recent tweets from that area on that subject.
Well worth a look, could be useful for a lot of things...
Kids don't stop to ask things like 'but why would people join in?', 'how long will it take?', and especially not 'what's the ROI likely to be?'. Kids build lots of things, and they build them because, well, it looks fun to do. Some work, some don't, but they learn lessons quickly and move on.
If you can tap into that mindset, and involve your customers and fans, where you're building things in social media, you're more likely to build something that other people want to play with too.