iPhone Still Dominates Foursquare Usage; Android, BlackBerry Up And Coming

Foursquare is growing fast. Real fast. Traffic may be up as much as threefold over the past two months. But how are people actually using it? The main Foursquare account tweeted out stats today that give a nice breakdown of usage. It's just over a seven day span, but given that the service is now finally on platforms such as BlackBerry, is probably a good sample.