This was a project we did for CS352, Introduction to Computer Graphics at Calvin College. It works best in Chrome, but can also work in Firefox 4. Browsers don't do a very good job of seamlessly looping audio yet, so the sound can be a bit choppy depending on your system.
Left/Right/Down (or A/S/D) can be used for turning left, right, and around. Space moves the camera up to third-person mode, though the controls remain first-person. Hold shift to look behind you. The + and - keys change how smart the ghosts are.