Also in your use, on Average how many pictures you can take before it dies?
I don't have a D40, but we have a D50, D70s and D200 in my house. They all get about 400 shots with minimal flash use. If you use the on-camera flash, the number goes down into the 200's, like 200-250, depending on the output.
You would be happier with at least a 1 GB memory card, preferably a relatively fast card, like the Sandisk Ultra II (60X) or Lexar Platinum (80X). There is no noticeable difference between 60X and 80X. Anything faster than these is great, but not essential by any means. If you think you will do a lot of shooting in the contiuous mode (sports, etc), consider buying a 2 GB card. They really don't cost much more anyway.
if you go to nikon website and look at the spec of D40, they should tell you the CIPA standard of the battery. the memory card that comes with the package usually is small.
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