This came from http://tweakguides.com/:
For now, the most important tweak has to do with the fact that VSync is automatically on and can't be disabled from within the game. This not only reduces FPS, it also introduces mouse lag. To disable VSync in Skyrim, add iPresentInterval=0 to the bottom of the [Display] section of the Skyrim.ini file in the \Users\[Username]\My Documents\My Games\Skyrim directory.
Just thought I would share!
Oooh nice. Why didn't I find that TweakGuide when I was googling? =/
Mouse lag from Vsync is actually not noticeable in this game (to me, anyway), compared to other games and to Oblivion. I can look where I want and point to what I want in the menu without feeling like I'm fighting the interface, so it's staying on.
