Unfortunately the answer is no and no. Foursquare returns the closest 50 venues, period. Facebook on the other hand is much better. They let you set a radius a

Unfortunately the answer is no and no. Foursquare returns the closest 50 venues, period. Facebook on the other hand is much better. They let you set a radius and a limit to the number of results you want. The limit can be huge, you just have to page through the results (max 500 per page). If you are interested, checkout apigee.com, they have a cool console that lets you experiment with multiple API's. What did you think of the Google Earth visualizations at the bottom of the blog post?