Hello!
This is a IR Led pen to Interactive Whiteboards?

http://www.amazon.com/dp/B00008BFS2?smid=AQK11O1HS2GGC&tag=dealtime-tools-mp-20&linkCode=asn

Thank's

There are some cheap LED flashlights where you don't even need to solder the LED so, you just change it for a IR LED very easily, and is a very cheap option, and a very good IR pen to have, hehehe. I haven't posted images of my IR pen, but believe me, it is really really very easy to do, you don't even need a resistor and some other things, just the LED and the batteries (because the cheap flashlights uses this wristwatch batteries and they are just connected without even soldering them, and they last a lot of time!!), and if you take the time, you can make it in a way that your IR pen will look very good.

Its been alittle while since I was here. I've been collecting keychain lights and converting them to find the best solution to this issue. I am a tech at an elementary school so durability is important to me as well as looks. I started building them and was told by "the system" that I am not a registered vendor so I could non sell them to the schools. I could sell them to teachers but what teacher in FL has money? Not many when they are laying them off. So I posted one on eBay and I may put the others up if it goes. I started the price below cost to see where it would go. Here's a link if you want to watch:
http://cgi.ebay.com/Infrared-stylus-light_W0QQitemZ290229670170QQihZ019QQcategoryZ14954QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Not sure why the link is so long. The item number is 290229670170