Hi there,
Taskfacade is a great program that you can link to a button with AE button plus.
This is the best way I have found to get from program to program.
Task facade can be found here:
http://forum.xda-developers.com/showthread.php?t=420220
AE Button Plus can be found here:
http://ae.inc.ru/aebplusdownload.php
Ae button can also be used to map other buttons to single, double, triple and long presses. Both are really friggin' useful.
Nb