This is the drop in
http://www.dealextreme.com/p/cree-xl...8-4v-max-26345. They are changing the catalog so that skus dont always work, but it is 26345. Solarforce may have something similar, I dunno.
I think
this thing might be able to be used as a diffuser. Probably not as-is, but cut off the lid and affix it to the front of the light.