Led drivers, Joule thief

I made a few boards of joule thief's, they can be used to light up a white led with a 1,5V battery (or even less).

Here are a few pics.

They are pretty small and can fit inside small DIY flashlights etc.

http://www.ebay.com/itm/161080170207?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649