Power device from USB?

Hi All,

I have decided that my next project will be to find a new way of supplying power to my networking switch.

According to the output specs on the AC power adaptor, it outputs:
7.5V === 1A 7.5VA

Input will be from a USB socket on a computer, which from memory, is 5V and 500mA. (Someone correct me if I'm wrong here...)

So I need to go from:
5V to 7.5V
500mA to 1000mA (1A)

How would I build a converter for this, and what components would I need. If a small diagram and explanation could also be provided, it would help me as I am only a 'newbie' with electronics.

Thanks in advance,

You can't suck more current from USB then 500mA (5V)
When You apply a step-up converter, it can't enhance the USB original power capability. For 7.5V 1A need 5V with 1.6A.

oh well it was good while it lasted...

my next mod isn't 100% related to electronics, but...

I need help with the wiring config of a standard phone line (Australia)
I want to hook a PC headset up to a phone line, so I don't have to hold the massive headset

If anyone has any ideas/queries, please reply and will go into more detail.

Thanks in advance,