How do I make my MacBook Pro run faster? Would a defrag help?

Computers DO NOT "run a little slower" over time, unless you're doing something wrong. (I have servers that have been running for 7 years (since we moved into this building), and they're as fast as the day they were first turned on. (Granted, not as fast as a new cheap laptop, but still as fast as when they were new.) Of course we don't fill the drives to capacity, or download viruses, or have 50 programs running in the background, just in case we need one of them once a month. Those things slow computers down.