You need to assess your needs. If you're not going to be printing anything bigger than 4x6, you'll be alright with a 2mp, but you should always try to get the most that you can afford. If you get higher resolutions, you'll be able to crop the photos and get closer to the subject, which is always nicer. Try to get as much optical zoom as you can, with an absolute minimum of 2x, with 3-4 being more helpful. Pictures just look a whole lot nicer when you can get closer to your subject. Some of the Fuji's come with enormous optical zooms, like 5-10x. Disregard Digital zoom; it's just the camera cropping the photo for you, which is pretty much a gimmick. You can do the same thing but better with photo software in your computer. Also, filter out 'combined' zooms, where the salesperson says 'This cam has 6x zoom', but it actually has 2x Optical and 3x Digital, which 2x3=6, but not really.
MACRO is essential, as Monte pointed out. Nikon's are FAMOUS for thier macro capabilities. Most Nikon digitals can get closer than 1" to the subject, but be aware that you'll need supplemental lighting for any camera at that range. The on-camera flash will wash out the subject that close, if it can illuminate it at all. Something that works better for me, is to use MACRO at a range of a few inches and high resolution (above 2mp), then crop down closer to the geckos. There's where your higher resolutions will come in to play.
Digital Photo Review is an excellent resource for camera information. There are some excellent reviews and expert-filled forums that should be able to send you in the right direction as far as which camera may be best for you and where you'll probably find the best price.
Personally, I always recommend Nikon, but I've heard excellent things about the Canon A70 as someone mentions above. I've seen Nikon's as low as $179 and up into the $1,000+ range. I have a Nikon Coolpix 995, which I love soooo much. It has the split-body swivel design, but isn't sold anymore. There is a newer model with some more features. I also own a Sony U20, which is only 2mp, but fits in the palm of your hand, so it's easier to carry around.
This isn't the best picture, but it's a beautiful gecko. She's Kelli's now.

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Rob Jenkins
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