I have recently been using a similar case for my MDA from BoxWave:
http://www.davespda.com/reviews/other/boxwavemda.htm
I also checked out the Alu-Leather Flip Case for the MDA from Proporta for something a little "softer"...
http://www.davespda.com/reviews/other/proportamda.htm
Interesting mechinism to hold the device in the case for the Proporta case. The one thing about the ArmorCase that has been bugging me is the case lid when I am using the keyboard.