Of course, you can re-charge batteries in the field, provided you can find a charger to fit the battery. You don't specify your camera, but it will be best if it uses AA- or AAA-size batteries. A number of chargers work for those, such as the ICPG Model 04041 ($50). However, most digital cameras use odd-sized batteries. For those, you may have to buy a solar charger and THEN an adapter that will hold the battery and plug into the charger. And you'll also need to be sure the charger will handle the lithium-ion battery your camera probably uses, versus the more common NiCD or NiMH batteries. You're probably going to end up in Radio Shack for this one, or maybe Fry's Electronics.
But, just keep in mind how convenient your camera is, versus carrying all those nasty rolls of film that will last for months unexposed, store better images, and keep for generations!