What does "distance" refer to? Amount of miles? Radius? I can't find any documentation on it. What's the maximum limit FB will allow us to grab?
$nearby = $facebook->api('/search?type=place¢er='.$_GET['lat'].','.$_GET['lon'].'&distance=1000&limit=200');
Distance refers to the radius with respect to the latitude and longitude of the location in meters. As mentioned by Chris, the maximum is 50,000 m.