Hey, I just found this software...and I was a bit impressed.
It is called SMath Studio. It can open xmcd files and essentially functions like the active worksheet mode of Mathcad.
I just thought I would put it out there. I don't know how often the engineers in the crowd try to access their mathcad/matlab/etc files on their mobile...but I thought it was interesting.
Anyways...here is the link
http://en.smath.info/forum/default.aspx?g=posts&t=131