Being shocked by notebook computers

I mentioned to Cindy yesterday that I am frequently shocked by my notebook computers, and she was incredulous. When plugged into wall power, both my old Thinkpads (T series) and my current MacBook Pro produce streams of electricity that feel like constant needle pricks (not jolts, but a sustained pinprick). The shocks usually come from the corners of the top cover (LCD area), and along the front edge of the bottom of the notebook (in front of the keyboard). Having your forearm shocked as you type is not a pleasant user experience! I only feel the shocks when I'm plugged into 240V, but my Mac is currently shocking me when plugged into 110V as well. Has anyone else experienced this? I've spoken to at least two people who have reported similar experiences, but it seems that most people haven't ever had this happen. It's happened to me on more than three separate notebook computers, so I have concluded that it can't be specific to just my machine.

Maybe my skin is extra-conductive.