I discovered while trying to set up my whiteboard system that an LED maglite (mini maglite) works well to test calibration; (turn it on, cover the bulb with your hand, uncover bulb when you need to point to a calibration point on screen), I don't know why the maglite led works, but it does.

I think this is a good tip for those impatient people like me who wanted to make sure the system works; before tracking down an IR LED pen, or investing money and effort into building a pen.  (that is, if you already have a mini maglite lying around)

This does not work as a permanent solution, obviously, but it seems to me that it may be possible to hack a maglite to function as an IR pen; the plus side is that the LED is very easy to change if it goes bad, rather than re-soldering.

there may be some other flashlights out there which use a partial-momentary push switch on the side...

technically, you can use a lighter to test calibration as well, but this is only what I've heard.

I'm thinking that it may be possible to re-configure the battery cap in a way which adds on an external switch, though the way to do so is beyond me at this moment.

edit
Please read: http://www.wiimoteproject.com/annoucements/moved-posts-and-posting-to-the-correct-thread-*please-read-me*/ this is the second post I moved! This post like the last has nothing to do with Bluetooth or knowledge, its an IR-Pen question. benpaddlejones