Hi everyone. I own a 2008 20" iMac. It's very slow and clogged up and I want to get the best out of it rather than purchasing a whole new iMac. I use it mainly for safari, bbc iplayer, youtube and my photos. It's currently running Snow Leopard. My daughter upped the RAM from 2gb to 3 a few years ago. Someone mention 'defragging' to me.. I'm not entirely sure what that means. Would anyone be able to recommend what I should do/ buy to improve it's performance as much as I can, without breaking the bank.