my MacBook is running REALLY slow, how do i fix it or make it faster.

i have leopard osx 10.5 on my mac and 120gb hard drive with half of it filled on itunes, movies and misc. other stuff, is there any way to check my computer for virus and if i do have one clean it up? also do cooling fan pads work to cool the hott running computer? thanks alot =)

You don't have to worry about virii...that's a windows problem. You could download onyx and run the maintenance options. Also how much ram do you have. OSX loves RAM so more the merrier. If my macbook slows down i just run onyx and it's good for another few weeks.