The other day I was looking at a USB cell charger from ThinkGeek. A battery that charges while it is connected to my USB port. But I found most took to long to charge or they where expensive.
I found project started by Stefan Vorkoetter that shows up to create a fast charger for NiMH/NiCd Cells USB Powered Charger for Two AA NiMH/NiCd Cells
The project looks pretty simple and I plan on trying it out this weekend.