Looking for an algorithm to cluster 3d points, around 2d points

Looking for an algorithm to cluster 3d points, around 2d points

I'm trying to cluster photos (GPS + timestamp) around known GPS locations.
3d points = 2d + time stamp.
For example: I walk along the road and take photos of lampposts, some are
interesting and so I take 10 photos and others are not so I don't take
any.
I'd like to cluster my photos around the lampposts, allowing me to see
which lamppost was being photographed.
I've been looking at something like k-means clustering and wanted
something intelligent than just snapping the photos to nearest lamppost.
(I'm going to write the code in javascript for a client side app handing
about (2000,500) points at a time )