I've had the question from a number of people:

"Jason - I bought a Windows Mobile 5 device - XXXXX - it says I have 64MB on the box however when I go into Control Panel - I only have 50MB left...."

Mike Calligaro over on the Windows Mobile team blog wrote this interesting article on where your memory on WM 5 is used ....

http://blogs.msdn.com/windowsmobile/archive/2005/11/17/494177.aspx