Longitude/Latitude for Stream items plus Radius filter

Hey there,

was thinking about re-designing my slow running community with a new feature and came across this idea. I think this would be awesome to be able to filter stream items by radius. This should not be too hard to implement since longitude and latitude are already stored so the filter would show items created by users within the given distance. Would be great in many ways for neighbourhood like communities, date finder, friend finder and many more communities.