I want to do a more comprehensive review on flashlights, but I wanted to post up a quick note about these since they are so good. I was in search of a flashlight to keep in the car's glove box and one to keep in my purse. Instead of using AAAs or AAs, I decided to go the Lithium Ion battery route. I settled on the Ultrafire SK98 lights with the Cree XML-T6 LED and that uses a 18650 battery. It is a great little light but has three nagging flaws:
It scuffs rather easily
It can get hot (not sure when/why but it does sometimes)
Turning it off doesn't reset it to simply "on" at full brightness, meaning the strobe can possibly come on the next time you turn it on.
Check out the product and my amazon review. I'll probably have a more comprehensive writeup sometime.
Link:SK98 Flashlights at Amazon