Comment 3 for bug 270193

This bug has been reported a long time ago to nvclock dev, but no new release is available since this time.
Here is the patch for src/backend/nv50.c:

    139a140,146
    >
    > //Temperature support for G92
    > if(( (nv_card->bios->device_id&0xff00) == 0x600)||( (nv_card->bios->device_id&0xff00) == 0x610))
    > {
    > temp = nv_card->PMC[0x20008/4]&0x3fff;
    > return (-13115 + temp) / 18.7 + 1;
    > }

You can find more information about this patch, including a .deb for 8.04 which works with 8.10 too for quick test, here:
http://computersstoneage.blogspot.com/2008/06/asus-nvidia-8800-gt-gpu-temperature.html

This solution is accurate for my Asus 8800GT and is based on the formula used by Asus, which is used by Rivatuner too.