rodmeister,

What latitude are you at? I'm at 45 north (twin cities MN), and early last fall I gave firemaking a try with fresnel lenses, and didn't have much luck, and certainly not with the credit card sized ones.

A fresnel lens is useful if you bring a small survival handbook and normally need reading glasses. The lens can serve as a backup to your reading glasses. Their use as a firestarter is secondary.

I found one place to order them online: http://3dlens.com/