I wanted a fan to help keep my PS3 cool, I bought this item and I have to agree with other reviewers that it is not the best fan to buy to aid keeping it cool. However, if you are using this in conjuction with another fan the two work very well to keep the PS3 cool. I bought this and am using a "USB CRYSTAL 3 Fans Cooler Pad for Laptop, Notebook, Xbox, PS3" and it keeps the machine VERY cool, for a decent price aswell.
Like has been mentioned before, the fan on it's own does not provide a lot of wind but it is there to work together with the PS3 side fan so therefore helps the hot air exit the machine.
It fits onto the side of the PS3, if you are facing the PS3 it will fit on the right side next to the power button and disc drive. It doesn't clip onto the existing fan area on this side which is very annoying but it has a little tray on the bottom that will help it cling to the bottom of the PS3 and so as long as you don't move the PS3 a lot it will stay in position. It comes with a USB connecton, the wire is extremely thin and so does look a bit flimsy but it is sturdy.
This fits the original PS3s, so won't help you PS Slim owners I am afraid.