Best choice for a digital camera

All, my wife has just told me she'd like to have a digital camera for Christmas. I doubt that I'll use it much, since I am pretty committed to film photography at the moment, but given a choice of what is out there, which camera is best suited for astrophotography in the 3-5 megapixel range? I'd like to keep it at 5-600 dollars if possible. Who has the best deal on mail order? All my other stuff is Nikon. Thanks in advance for your input.

Mike V.

Our local Best Buy is now listing the Coolpix 4500 at 599 which is 100 less than I paid 6 months ago. There is a 50 rebate program currently on, but this price may already include that, can't remember.
Anyway, I am very happy with mine. Of course, if I had the bucks the Canon D60 would really be nice!!

Walt