I checked the links-the Pila looks pretty good, although they didn't give much info on it; they didn't list 18350 or 16340 batteries, but as Ratchet said it comes with a spacer, so one could assume.....
The Xtar also looks like a good unit; the review was a little too technical for me, but I think I got the gist of it-I don't understand the usb port function though; it says you have to have a battery in one of the slots for the usb port to work, but they don't really explain how it works-does the battery merely complete the circuit, or does the battery actually power the usb port, even if its unplugged? If the battery actually does power the usb port, that would be a handy feature-I could charge, say, my cell phone or my Inferno when I'm away from a plug.
Thanks for the suggestions everyone.