SciLor’s LeoCameraAnyKey is a tool that allows you to run the camera/camcoder function of your devicem but you can now use the volume keys of the HTC HD2 aka. Leo to make your photo/video. It may work on other devices on many keys. Now you may use it just to zoom in and out.#

Changes:

v0.2 (2010-06-04)
-Feature: Disable Splashscreen
-Feature: Zoom
-Feature: Custom click position for the camera to support any resolution.

http://forum.xda-developers.com/showthread.php?t=693433