If you have an iPad or iPhone 3GS+ then this is the car charger for you. The Griffin PowerJolt and PowerJolt Plus allow for full 2.1 amp charging via a 12 volt source. Also, the passthrough socket will allow you to plug another charger or device in through it's passthrough port.
My favorite thing ( besides rapid charging) is that it seems to run cooler than any of the OEM chargers. 
Charge rate was most noticable on my iPhone 3GS where the charge level increased around 2% per minute during the phase 1 charging. The ability to fully charge my phone in about in hour means I don't have to top off every time I think about it which is detrimental to long term battery life.
iPad charging was good and it was able to charge the iPad while it was awake and busy. Some chargers or cables don't have enough juice or throughput to charge the iPad while in use. This one is 'a-ok'.
