Snow Leopard 10.6.8 - 2.3 GHz i5 - Mem 4GB We all know that when you delete stuff it doesn't really go, so how do you clean up so the machine runs quicker and smoother after you've deleted stuff. I deleted 175GB off of my 350GB MBP and certainly wasn't going to do a 'secure delete' which I assume would've deleted it properly, as that would've taken about a week. So what do you guys and gals do to delete space. I'm not going to get full speed and smoothness just by emptying the trash, regardless of how much was in there, as I say, because we know it's still on here somewhere. I know you don't trust the apps that promise 'clean up', but is there anything you do within the MBP itself to do this? I'm talking machine actual, not deleting internet history, obviously. I hear of running scripts, but does it actually do this and when would it, I don't leave the MBP on, and would that actually clean up what I've discussed anyway?