What to get with a Nikon D3100?

I finally decided on the new Nikon D3100 after weeks of comparing it to the Canon T2i and other models… I'm picking it up at Best Buy tomorrow, and wanted to know if there's anything else I should buy with it at the time of purchase (other than insurance).

Can anyone recommend a good carrying case (or does it come with one?) and tripod, or anything else that most find a necessity with their DSLR?

I think I'm gonna hold off on another lens for now (it comes standard with the 18-55mm zoom lens), but please feel free to recommend any you think are great.

Http://www.amazon.com/Photography-Dummies-Second-Russell-Hart/dp/0764541161/

You can consider extra batteries, tripod. Vista Explorer 60" Lightweight Tripod
http://www.amazon.com/...B000V7AF8E
http://rover.ebay.com/...m270.l1313

Nikon d3100 is one of the best dslr cameras i've ever seen