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Re: the non-flammable solution-
I just finished building my own "sensor" bar from 4 radio shack high intensity IR LEDs (part # 276-143). It works very well as a source for the Wiimote - I just did the calibration in the preferences once and I was off and mousing!
The advantage of the DIY method is that you can choose your power source. I wanted an AC plug powered unit that I could connect to my switched outlet on my A/V receiver so that it would power off automatically when I am not using the HT setup. But you can build one that runs on USB (5V) or batteries - your choice.
Here are some good links:
http://e.inste.in/2007/04/13/building-a-wiimote-usb-sensor-bar/
http://ourworld.compuserve.com/homepages/Bill_Bowden/led.htm
http://terbidium.com/content/projects/wiihacks/usb_sensorbar.php
The trick is to know the number of LEDs, their voltage drop (1.2 V) their forward current (29mA) and your power supply voltage (an 8.2VDC wall plug from an old mobile phone charger in my case). Then just use the calculator (second link) to figure out what size resistor you will need.
Hope this helps-