8lb desktop?! My Notebook weighs 11lbs! And that's without the power brick. It's the first thing I take out of my pack when I'm cutting weight. I typically carry a 4GB USB key with the important stuff encrypted...it's hard to go anywhere these days without finding a computer...but as Eugene said you take your chances doing that.

I have about 1GB of security apps on mine so I can scan for viruses and spyware before decrypting/extracting anything I may need. Even have a portable version of Firefox with a built in Onion Router client for somewhat secure internet communications.