Are 3gs chargers compatible with iphone 4?

[kevlar]

Can anyone confirm wether last years power accessories ( i.e. wall chargers, car chargers and battery packs ) work on the iphone 4? last year I had to get a new car charger and battery pack ( like this one 5000mAh Portable Power charged by computer or usb dc charger, and charge for iPhone/ iPod, Blackberry, PSP/ NDSL ) because I was getting the ' this accessory is not compatible ' message on my 3gs.

 

[kevlar]

After finally receiving my ip4 this afternoon I've been able to test this myself, my 3gs car charger and usb external battery pack seem to work fine. Thank god.