Just converted two Scout backups from Halogen to LED
Info on conversion available here
http://wobbelunch.multiply.com/photos/album/1/Slumpy_2Imported the R2 leds from here
http://www.dealextreme.com/details.dx/sku.11836 Took about one week to arrive, postage free.
Had trouble finding the correct size head spacer as new bikes tend to have 1 1/8 spacers.
Finally located some spacers with the correct outside diameter ie to match the original halogen, but inside diameter was larger than the LED drop in.
Got around this by moving the LED to be hard against one side of the spacer and filling the void with ferropro epoxy mix.
A bit agricultural but it works.


Note that in the second pic the small spring has come away from the back of the LED but just needed to be resoldered.I have added a couple of extra dobs of solder to strenthen this area after the pic was taken.
Once ferropro hardened just touched up with dremel.
Have to be careful that the drop in LED makes good contact with the inside of the spacer as ferropro is not conductive.
Total cost for two lights $22.00.
Results are great. Conversion on left, Halcyon conversion middle, Halogen right.
All with new batterys.
Thanks to Pete's site and post on Dive oz for the starting details.
Cheers