Bringing home a desktop computer for working remotely doesn't require a desk, as long as you have an LCD monitor:
http://www.airdesks.com/computer_desk.asp
I bought the basic air desk for my laptop a few years ago and moved my "office" to the living room -- fabulous convenience and comfort, and I'll never go back!
My experience is that the fact that you're not hunching forward (as at a desk) changes everything: it's only the weight of the arm, not the entire upper body. I have a heavy laptop and lean on it a lot, and the stability has worked for me. The base of the stand is huge -- not like it's gonna tip over.
I actually have the airdesk for workstation sitting here in its shipping box, waiting for me to set it up; once I'm all set up, you're welcome to check it out and lean on it! Also, might do to just email those folks... probably a common question.
How sturdy is the Air Desk
This looks like a winner. I tend to rest my paws on the keyboard/laptop which of course would include some of the weight of my arms. Would this be a problem if I do not have the CPU counterbalance option?