There are many ways to do this and I have tried most of them. I have found the easiest way is to use AE Button Plus.
http://ae.inc.ru/aebplus.php
It has many other features but I use this feature mainly.
For example I use the program to:
Button 2 (IE Button):
1 press runs IE
Long Press Rotates Screen
Left Soft Key
1 press (Presses Left Soft Key) normal operation
Long Press Switches Vibration mode on/off
Right Soft Key
1 press (Presses Right Soft Key) normal operation
Long Press Device Lock.