A couple years ago I posted about the Cen-Tech (Harbor Freight) 3-in-1 power pack for portable power. The one I have has served me well on camping trips to power radios and charge cell phones.
The old model looks like it's been discontinued and replaced with an improved version. Improvements include replacing the incandescent work light with an LED, two 12V ports instead of one, and adds a 2.1A USB port for charging cell phones, etc. I'm not going to rush out and replace my old model, but if you're looking for an additional or new portable power source, this looks like a good one.