[hAvAAck]

the phrase is soft key
http://forum.ppcgeeks.com/showthread.php?t=5108

23-Changing SoftKeys
Create the following keys and Strings in the registry:
HKEY_CURRENT_USER\Software\Microsoft\Today\Keys\11 2
HKEY_CURRENT_USER\Software\Microsoft\Today\Keys\11 3
112 is the left key and 113 is the right.
Set Default to what you want the key to read (ie. SMS)
Now for each key create a new string named Open and set the target path.

I believe there's another way to do it, but that's the way I use