Here we take a look at the DC to DC Boost converter from DealExtreme (SKU 149681). Will a gadget for only $6 be able to provide a stable enough voltage for charging a phone? The answer is yes, but only if you can live with the high pitch coil-whine. Which you probably won't.

Pros

• Wide input (3-34 v) and output (4-35 v) range
• Cheap (5.62 USD)
• Handles high enough currents for most applications

Cons

• Loud, high-pitched coil whine

DealExtreme product page
http://dx.com/p/dc-3-34v-to-dc-4-35v-adjustable-boost-converter-charger-module-149681