Taskbar Launcher is a little tool that shows a customizeable launch pad when you hit the taskbar.

Attention: Current version is designed for newer 6.5.x builds of Windows Mobile with the start menu on bottom. Taskbar Launcher is blocking all other applications from the taskbar, so it might be a bad idea to use it when your Start menu is still on top.

Changes:

Fixed bug: Taskbar launcher showed instead of HTC Volume Control (tested on Touch Diamond)
Fixed bug: Selected icons stayed selected when moving out of the icon
Taskbar is split up into 3 areas, each of them can launch something (see INI file)
Supported commands: switch to Start menu, switch to Manila
Added $ROTATELEFTBACK and $ROTATERIGHTBACK
Added switch to deactive Taskbar launcher (workaround if “Stop Taskbar launcher” leads to problems….)
Finally there’s link in Startmenu to Taskbar launcher (configuration tool automatically starts Taskbar launcher when finished)
More options in popup menu (see screenshot)
Added first-stage configuration GUI (see other screenshot

http://forum.xda-developers.com/showthread.php?t=621624