Paul from Modaco has already released an utility that adds all your applications in the start menu to the Shortcut Key configuration program. If you have not tried the utility, and just want to access you favorite application using the Shortcut key, here is what is to be done.
1. See HKEY_LOCAL_MACHINE\Software\HTC\HTCSideButton. You will see these string value entries named '0', '1', '2', and so on. Well, those are the programs that appear in the configuration program. Create the following string value (REG_SZ) key -
Name = the next number in the list, if you have numbers upto '4', then name this key '5'
Data = path to your favorite program; for example, \Windows\Start Menu\Task Manager.lnk
2. If you now go to Start>Settings>Shortcut Key, the application you just added (Task Manager for the example) would be an option listed for "Short Press" and "Press and hold". Select it the way you like it.
Repeat Step 1 if you want more applications to show up on the list.
Note: The name that appears on the list is extracted from the path that you entered as part of the registry key. For example, if I give the path as \Windows\Start Menu\Task Manager.lnk, then I shall see the name Task Manager in the list. Task Manager.lnk is actually a shortcut that points to \Windows\IA_Task_Manager.exe. I can as well give the path as \Windows\IA_Task_Manager.exe, but in this case the name would appear as IA_Task_Manager in the list...not so nice!! So, I used the shortcut.