Out of interest, I have one of these rather nice modules from TI on sample order.
They take between 2.95v and 5.5v as input, and output between 5V and 15V at 12W. That's 2.4A at 5V!
They're not cheap though, at $10.00 @ 1,000, but still very nice little modules. And all they take is a resistor to set the voltage (or none if you want 5V), and a couple of decoupling capacitors.