What that was quick? Facebook was stealth testing their "Find Friends Nearby" feature over the weekend that would show the Facebook users around you. But they may have just pulled the feature completely.
While there was no official announcement about the Find Friends Nearby and we did try to play with it, we found nobody near us, even we did have people next to us. Facebook told Wired that Find Friends Nearby wasn't actually intended to launch. They said:
"This wasn't a formal release—this was just something that a few engineers were testing. With all tests, some get released as full products, others don't. Nothing more to say on this for now, but we'll communicate to everyone when there is something to say."