One of the fun things about when I used to work construction was the little tricks you learned from the 'old' guys. When you plug something into an extenstion cord tie a loose knot in the cords before plugging it in. That way when the dog/child/clutzy co-worker/pickup hits your cord the stress is taken up on the knot rather than the plug.
Of course, that's not going to prevent it from being pulled out of the back of your laptop or the wall!
"I met Larry Niven at ConClave 27...AND I fixed his computer. How cool is that?"
(Memoirs of a geek)