Useless, but cool. Such is the life of most cool visual tools it seems. That said, I stumbled on this little gem when loading my twitter homepage, and they had an add for "find out what’s new" or something. At any rate, check it out.
I just found it two minutes before posting, so I haven’t played much with it, but when you click a friend’s little tile, it zooms into it, and shows what they posted, kinda neat.
The whole thing draws pretty damn sweet when it loads.