Mapkit with multiple annotations

I have a map displaying multiple ann开发者_StackOverflow中文版otations. I'd like to mimic the behavior of the Places tab on the Photos built-in app (iOS 4), where the annotations are automatically joined together or splited apart as the user changes the zoom level.

How do I do that?

Thanks!

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The specific clustering functionality that is used in the 'Places' feature of The Photos app is not exposed to developers currently. If your are looking for a magic library, sample code or the like to do this currently you are out of luck.

If you are very comfortable with MapKit and clustering techniques in general you could work on rolling your own solution or contributing to a public effort to achieve this.

Some things to look at:

iPhone Map Kit cluster pinpoints http://googlegeodevelopers.blogspot.com/2009/04/markerclusterer-solution-to-too-many.html