Yes. On the Nikon D300, the easiest way to do this is to use Interval Timer Shooting. Set the interval to about 1 second, then choose how many shots you want the camera to take. Once started, the camera will automatically capture the sequence, which works well for self-portraits when you need several frames in a row.

This is different from taking a long exposure or a single self-timer shot: interval timer mode is designed for repeated shots at set time gaps.