Hi Jeff,
Yes you can use putty and with the Raspberry and Beagle, putty has been fine, but I have a Scientific Linux box and when using Putty to display a gnome-session, it seems that putty and xming are problematic - the session freezes. No idea why.
However, I use Cygwin and Morton’s Cygwin Launcher (http://www.hostalive.net/cxlaunch.html) and it doesn’t have that problem and seems to have the added benefit of being able to use all of the monitors - putty and xming cannot be stretched across the monitors.
Trefor