About a year or two ago I remember seeing that someone had created a freeware alternative to TrackIR (it uses your webcam instead of IR sensors).  All of my searching has come to not, and I'm wondering if anybody remembers/knows what this is.

Are you talking about FaceTrackNoIr: http://facetracknoir.sourceforge.net/information_links/download.htm or FreeTrack: http://www.free-track.net/english/

?

I've tried out only FacetrackNoIr and it was a bust. It simply froze solid and did nothing else. It doesn't mean it won't work for another... it's only that that "another" it's not me, and I'm still put off by it. Have to find a little time to put together the IR diodes contraption to try and use Freetrack.

Have fun trying yourself.

I had a Track IR, but personally I found it irritating in use, and I prefer using the mouse to pan
( Shift + O )

But obviously there must be many users who are happy with the Track IR.