Android application to allow user map his location

In my app I ask user to enter his location(text) and call Google web service to find out geocodes and then display on map.

Now I also want the user to fine tune his location by moving the marker on 开发者_StackOverflow社区the map.

How can this be done?

Rgds, Sapan

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Please take a look at this source http://bazaar.launchpad.net/~financisto-dev/financisto/trunk/view/head:/src/ru/orangesoftware/financisto/activity/LocationActivity.java at LocationOverlay inner class in particular