I just found that great Windows Mobile application. AE Button plus:
This application allows you to map any function to the different hardware buttons. Instead of only controlling the Volume, I have set the VolumeUp button to open the Task manager and the VolumeDown button to do ALT+Tab, both on double click.
The amount of possible combinations is amazing. AEB plus also recognizes triple press and long press. This application is definitely a must have. You could for example allocate the camera function to the hang up button which is great if like me you are using the default Windows Mobile UI.