I've read what I can without much luck - and really I'm a SAAB newbie,
so please be gentle.

I was coming home from work in my 9-5 Linear (2002, 70k miles) when it
decided to not want to stay in gear any longer.  So  I crept to a halt
in the middle of an intersection.  The automatic shift lever will move
up and down the gears, but it wouldn't engage.  I turned off the car -
sat stewing while being honked at - started it back up again and was
able to put it in gear long enough to at least get it out of the
intersection.

Did it a couple more times so that I could get the car no longer
rolling backwards (big hill) then pushed it into a parking lot.  Had
it towed home - since the nearest dealership is quite some distance
away.

Question is:  What in the heck happened?  I've read about this "shift
interlock" problem - but am not sure that's the same thing - could
this be it?  If so - how can I check/fix it?

Any ideas? Suggestions beyond towing it to the nearest dealer (50+
miles away) and waiting for the 3k bill?  Of course, if that's the
only alternative - c'est la vie, dealership here I come.