https://picasaweb.google.com/lh/photo/8Tw-ARLAxMXklhb4qdAXZFb0Fup7skO_tfHKEcVdaS4?feat=embedwebsite
I used a tiny led from superbrightleds.com.
Bright as crap and you can't even see it stuck on the back of my taillight.
Best part is it was $1.99 - I bought 6 of them.
http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&category=ACCENTS&Page2Disp=%2Fspecs%2Fld1-x_alm.htm#photos