You could use a wall charger with a USB jack as the above poster said, or you could get a wall plug to cigarette lighter adapter like this:
http://www.amazon.com/SEM-AC-DC-Wall-Plug-...r/dp/B000EG8RIM
$0.64 + about $2.98 shipping, claims to be rated for 1 amp, but read reviews before you buy this one
http://www.dealextreme.com/details.dx/sku.2705
$3.36 with free shipping, good for 1/2 Amp
I've had good luck with Dealextreme, but they can take anywhere from 1-6 weeks to deliver.
http://www.eforcity.com/dothacdcad01.html
$3.99 with free shipping, no Amp rating
You probably need less than 1/2 Amp to run/charge your eXplorist, but you could use the adapter to run other devices that have a cigarette lighter plug and the more amps the adapter is rated for, the better.