Well, you can write your own monitoring program:
Nvidia has "freed" (as in freedom) "nvidia-setting" a long time ago:
You can get the source (GPL Version 2) here
(although, it seems nvidia **** ** the code, when they're added xrandr to it, but still can get the older one with google)
I've already hacked it a bit... and made a little addon for ksensors...