Normally, I would have put this in the comment section, but it was an obscure discovery that I thought few would know and many might want to know.

I recently did a bloggerview with David Hill. In the course of the discussion, the thinklight came up. It turns on by pressing the function key (left bottom key) and the PgUp key (upper right key). A very relevant comment came up that it would be good to not have to use two hands to turn on the light. I saw this as a handicap issue for some, but it was pointed out that holding coffee (or a beer for some of you) in one hand makes it also un-accessible.

I sent the note to David as a design issue, and the following came back from one of his team members from the design center. I’ve used PC’s now for 26 years and didn’t know this:
Fn key lock function
The Fn key lock function gives the same effect as pressing and holding the Fn key and then pressing a function key. Start the ThinkPad Configuration Program. Click the Accessibility Options button, and click Enable for Fn key lock. You can also set up by typing PS2 FNS E at the command prompt. If the Fn key is not locked, you must press and hold the Fn key while pressing a function key in order to perform certain tasks. If the Fn key is locked, you can use the function keys as follows:

• Press the Fn key once. Then press a function key. You can get the same effect as if you had held the Fn key down while pressing the function key. The Fn key has to be pressed again each time you want to use the function.
• Press the Fn key twice. Then, for the rest of your session, you can press any function key without pressing the Fn key again.