Take a look what i just found today at amazon:
Their description:
Product Description
Plug the iPhone Standard Travel Charger directly into the phone, cradle or desktop charger stand to recharge to your phone. Charger specifications are the same as the original charger that comes with the phone with enhanced internal circuitry to manage ch… More >>
Go & get it here - i can recommend it:
Apple Car Charger for iPod iPhone 3G 3GS
I can confirm that this charger works with my iPhone 3GS. It does feel a little cheap, but dang, what do you want for 1 cent.
Needed a car charger for my iPhone 3GS (32 GB).
Price was right and arrived quickly.
Works great - no complaints!