It'll give you the option of installing commonly used and large files to the hard drive when you first run it.
Niky,
Is there a way to tell whether I've done this or not? Cuz I really don't remember that option when installing?
Also, in defense of the peole saying it is "wearing out their laser" It could be a couple of thngs....the laser can be dirty (it does get dirty) and also the platter can get wonky. All disks are not made perfectly balanced.. And after years of playing, especially if you had an especially wonky disk, it can unbalance the platter rotation mechanism. It doesn't have to be a lot, even very slightly...but then if you put another wonky disk in there that is wonky in a different direction it can cause even more problems.
In short....before you go out and buy a new playstation, try insterting your disk in different orientations....like a clock. Start at 12, if you have problems move to 1, then 2 etc. Eventually you may find an orientation that stops your problem. High end cd players have very beefed up platter systems just for this reason....and it's not a platter system sony is using I assure you.