Sunfire - Manual Shifter

My fiance was driving our car and after a slight grinding of the gears the shifter pretty much stopped working.
The car is now stuck in gear (I believe 3rd) and the shifter stick has absolutely no effect. The stick can not be put in the position of 1st or 2nd. It simply won't move over that far.
Is this a big issue or a small one? Is it just a linkage issue between the shifter and the transmission?!?

Any help would be GREATLY appreciated. Thanks!

It's possible that it's a linkage problem, however since you say it is stuck in 3rd gear, I fear there may be more damage. I had the same thing happen on my Toyota Camry 5 speed only it stuck in reverse, Have to replace the tranny now, gears locked.

It was the Shifter Cable. Whatever the hell that does. $70 fix. $1.25 for the part....the rest in labour. Highway robbery!
Anyway...thanks for your help.
If anybody knows what the purpose of a shifter cable is, please let me know. I'm quite curious.