I built a tool/rig for creating boom style camera moves in Maya. This can be used directly in maya, or baked out for use in an engine (I initially made this because the camera controls in UDK were very lacking).
The idea is to constrain the camera movement, because often you see cameras and camera moves in 3d/games that feel like they're 'floating.' These generally don't feel right to the viewer, and one solution I thought of for helping minimize this is constraining the camera movement to something more comfortable to the viewer.
Feel free to download the script at my site here: http://www.tylergood.net/reelcam-rig/