Nikon d90 possible to program camera to shoot pic automatically?

I want to program my camera to automatically shoot a frame every 6-10 seconds (time lapse) for a specified duration of time or # of frames?

You need an intervalometer function which the D90 doesn't have. You can tether (USB connection) your camera to a computer and use software with an intervalometer feature to control your camera. Nikon's overpriced Camera Control Pro does this as well as some much cheaper alternatives and free control programs out there.

If you shoot for a long period of time, you may need to use an external power source for your camera.

The D90 by it self dose not have the function alone but here is a good device that connects to the camera http://cgi.ebay.com/...4aa68404f4

you want to use the Interval: 1s to 99hrs 59min 59s in one-second increments feature.