I bought a Nikon d3100 but it didn't come with a usb cable?

The box doesn't say it's supposed to be in there and it wasn't in there either but on nikonusa.com it said on the list of accessories, a usb cable is supposed to be in there. And even if it's not supposed to come with it, how am I supposed to put the pictures from the camera on the computer?

The best thing to do is buy a USB memory card reader (walmart/BestBuy/CVS/etc.) instead of a USB cable and then:

1)Download the memory card content to your computer using a USB card reader
2)Verify the transfer was a success
3)Back up the files on your computer to another hard drive (or CDs)
4)Format the memory card with your camera

Do this at the end of every day that you take photos/videos.

Demand one from the store. You could get a replacement from any computer supply shop if it's not worth going back. The best way to transfer files from the camera to the computer is through the use of a USB memory card reader. That's the only method recommended by computer experts.

The card reader is a good solution. I have packages from cameras that have the cables in them that I never use.
However, it makes me wonder, if this was sold as brand new why the cable was absent.

I bought the exact same camera yesterday, and I had the same problem. Because my computer will read SD cards but not SDHC, I had to put the card in my cheap digital and transfer from it, but I'm afraid if I have to keep doing it this way I'll lose picture quality.