Nikon D3100 SD Memory Card?

I currently have a D40X and I'm thinking about upgrading to the D3100.
I have a 2GB SanDisk Extreme III SD Card: http://shop.sandisk.com/store/sdiskus/en_US/DisplayProductDetailsPage/CategoryID.13313800/productID.104615200

I think it's fast, but how many RAW file can I take with the D3100 approximately? The Nikon D40X is 10.2MP, and the D3100 is 14.2MP.

I'm not really interested in video recording

At ten megapixels you would likely fit around 120-140 pics on 2gb, so at 14mp you would be at the 100 mark, maximum.unless you shoot in black and white, which would result in a marginally smaller file size. Go check out www.lowpricememory.co.uk and get yourself a 4 gb card for next to nothing.

I usually get about 150 photos at 10 mp on a 2 GB card in RAW shooting. I would guess that with 14 mp would decrease that by about 40% or so.

One minor correction to what f_j_hunter said: When shooting in RAW, your file size will be the same whether you're shooting in color or b/w. There's a difference in file size of color or monochrome ONLY when shooting in JPG. Even when you tell the camera you want to shoot in monochrome, all the color information is still in the RAW file, kind of like the white balance info, which you can also change later in post processing.