[lepht]

I can appreciated GP's optimism, but as someone who has actually utilized both data sets in various forms this is spot on.

Foursquare's data is vastly superior, something I attribute at least partially to the fact that they've built a service that incentivizes checking in, while Facebook is more heavily scrutinized for their questionable privacy practices. It'll be interesting to see if this continues to be the case when 4sq releases Swarm.