I actually press the top part of L2 or R2, the sort of edge or corner so I have lots of purchase instead of trying to press the flat face where my finger will easily slide down. It works fine with said adjustment to cope with the controller's flaw.
Also the 360's sticks are better for aiming and not losing purchase, those controllers seems to have a recess cut into the stick with four dots so you can get a quick and easy feel to which direction is perfectly straight forward, or left, right etc. I sometimes slide off the Ps3 sticks, especially in games that I have to hold forward or sideways for an extended period of time.
I'm tempted to buy those trigger extentions and cut a groove into my Ps3 controller's sticks : P I was even thinking of trying to get one of my xbox controllers and combining it's casing with my Ps3 controller's innards :D
Atleast the D-pad is better! And no batteries!
