Regarding iPhone Map Kit cluster pinpoints:
I have 1000\'s of marks that I want to show on the map but it\'s just too many to handle so I want to cluster them.
I tried the others suggested here, and I also found OCMapView which has worked the best.
Its free and allows for easy grouping of annotations, which is what I needed. Its a bit newer & more updated than Revolver and to me is easier to implement.
You can use REVClusterMap to cluster