Found this earlier. This allows the people with the early 2008 MBP and MBA v1 to use the 4 finger swipes that Apple only currently offer for the Unibody machines (even though these older machines have the relevant hardware support). (This only works on machines that already had 3 finger multitouch gestures).
When they first added 4 finger support I was annoyed they didn't give the update to existing machines. At the time it was quite a fiddly process to get the older machines hacked for this. This whole procedure took me less than 10 minutes and only involves copying/overwriting a file and then repairing disk permissions.
Now I can use 4 fingers up for "Show Desktop" and 4 fingers down for Expose. Handy as I had these allocated to the bottom 2 hot corners.
http://www.super-poultry.com/2008/12/4-finger-multi-touch-for-older-mbps/
rp2000
When they first added 4 finger support I was annoyed they didn't give the update to existing machines. At the time it was quite a fiddly process to get the older machines hacked for this. This whole procedure took me less than 10 minutes and only involves copying/overwriting a file and then repairing disk permissions.
Now I can use 4 fingers up for "Show Desktop" and 4 fingers down for Expose. Handy as I had these allocated to the bottom 2 hot corners.
http://www.super-poultry.com/2008/12/4-finger-multi-touch-for-older-mbps/
rp2000