This is a clone of Adafruit's Mintyboost that I made to take to Glastonbury last year to keep my phone charged. It's basically the suggested schematic and layout from the LT1302 step-up converter. It turned out pretty well - I like that its not much bigger than the two AA cells it runs on. Could do with a nice 3D printed case for the component side perhaps.
Performance wise, it was a bit disappointing. I think that was quite a lot to do with the crappy batteries we took with us and that were available on the site. I didn't actually test it very much. At some point, I'll get around to doing a proper test with various batteries.