Isnt a shame so many gadgets expect you to have your computer on so you can charge them. It almost makes sense now to convert all your home plug sockets to USB sockets. Well, until that is feasible you can purchase the USB Mains Charger.
Forehead slapping easy, just plug into your mains plug socket and then insert your gadget's USB plug into this minimal 21st century plug and hey presto electricity is whooshed into your beloved gadget.
Use £5 gift vouchers, various available in the vouchers section, or if you got the Firebox catalogue a week or two ago, they've doubled the voucher value till midnight on the 19th (so for example, I had £3 vouchers which took £6 off my order today!)