I created this because I was curious of what people were doing at the same place I went to. Now I'm using it also to see pictures of a specific place, I think it beats google image for image search of a specific location.
I hope you will enjoy it and do fun things with it!
How often are the images pulled? Could they be sorted by date? It would be interesting to see the flow of pictures in real time during specific events.
Polygon/radius is more of a problem interface-wise. For now I'm trying to have the maximum density of pictures (so you always find relevant things) and I think that's what people are looking for.
I want to add sorting and real time in the future (especially for things like concerts, would be so cool). For now I keep adding APIs, I'm trying to add Facebook/Twitter/Vine for now.