I would combine a car charger like this:

http://www.mobileplanet.com/product.asp?code=139874

with a empower socket converter like this:

http://laptopsforless.stores.yahoo.net/airpowadcor.html

I also googled up a USB charger, so if you carry a laptop around this might be useful:

http://us.yesasia.com/en/PrdDept.asp...id-1004434977/