I have a Macbook OSX version 10.4.11 with a 2GHz Intel Core, 512MB 667 MHz memory, 80gig capacity. Purchased in spring of '06 for $2100. I want to keep this computer running nicely and at a fast speed for as long as I can. Like an old dependable car. I want to make some upgrades to make sure the software stays relevant with technology and to ensure that I am taking care of it properly. Right now, I basically use it just for the internet and music. But will soon be using it for school (Industrial Design major). I do not know much of anything about what sort of upgrades I should do. (Applecare has expired also) Any suggestions/tips will be GREATLY appreciated! I have about $300-$400 to work with. Also- the only two problems with my computer are: Only stays on when plugged in. (Getting a new battery) CD drive does not work. (Liquid damage) But I rarely have the need for it anyways. Thanks!