Can you charge a iPhone 4 with just a car battery(no car) with just hocking up a car 12v jack to it??

I'm interested in this as well and would love to hear from someone that's done this. We're you able to get it to work?

I'm interested in using iPod Touch's for extended length time lapse movie generation for 12 month+ periods. I'd be placing the iPods in difficult to get to locations so I'd like them to continue operating for at least a year on a single battery.

If you use an Iphone car charger to power the phone. It will convert the 12 volts to the approx 5 that the ipone needs.

Let's get this straight, if you are planning to use the car adapter for the iPhone, (12 volt to 5 volt converter) and hook it to the battery and the converter plug to the iPhone, you can if you keep the polarity right.
If you're asking if you can hook the iPhone directly to the 12 volt battery without a converter, nope, you'll fry the phone for sure.

. Yes (as long as the car battery is charged up), but you REALLY need a fuse or circuit breaker in the circuit (kelseymh's 300 amp max figure would be for a very small battery). A 5 amp fuse should work well.

Why do I have this horrible picture in my head of a set of jumper cables, where you've cut off one end, and soldered the 0-gauge cables to the leads of "cigarette lighter" socket....

A car battery can deliver up to 300A at 12V.