Some fender eliminators come with a light:
the targa (the one I have) has a small LED plate light. It's probably enough that I'll pass inspection, but it is definately not enough to properly illuminate the plate at night. I havent been pulled over about it yet, though. Come to think of it, I dont have a plate light on my pickup either, and I've never gotten ticketed for that (had it like that for nearly 7 years!)
If memory serves, the hemicad one has a plate light.
Of course, the OEM one uses the OEM plate light.
Or, you could use something like this:
http://www.1tail.com/sa/p/Lite_N_Boltz_domed_head_license_plate_light_-_Satin_Finish_(pair).htm