A guy named Vijay made available a tiny software hack for the Windows Mobile remote desktop client (mstsc40.exe) to enable full-screen support.
WM2003 and WM5 compatible and works in QGVA or VGA, landscape or portrait.
It's a beta. In that, it's got issues and it's not final.
I'm going to add scrollbar hiding and some navigation bits and bobs and some other stuff.
Usage is easy, but this is only for advanced users right now for reasons forthcoming:
Load VJFullscreenTSC. I recommend putting it in your Start Menu or assign it to a hardware button.
For more information and the download
visit his site.