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.

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