How can I disable visual effects in Lion? I've just installed Lion on my 24" iMac from 2006 and do have again problems with screen-freezes due to overheating. This is a known issue with the 2006 iMacs since OSX late 10.5 / 10.6. While for (Snow) Leopard it was possible to overcome this problem by deactivating a kernel extension of the graphics card driver, this does not seem to have any effect with Lion. 

How do i disable visual effects with Lion, such as smooth window-moving, drop-shadows everywhere, window-animations, smooth video playback etc.?

Thanks so much!

UPDATE

I just wanted to make clear, that I have already tried some UI tweak applications like Cocktail and iTweax. While they are able to disable some animations, the most "expensive" effects are not turned off (at least not as far as I know) like smooth window moving and drop-shadows.
The place to go to disable animation is in the Secrets preference pane. You can disable a lot of the animations. Has a few Lion preferences and is updated in realtime from the community.