Some people think you should move out of the pool after you had bad luck, and go back after you saw other people have good luck. But that's not really helping you. That is NOT how pool hopping is done.
"Pool hopping" is a specific term that doesn't just mean switching between pools. It means switching between them at very specific moments to abuse weaknesses in their reward systems so you can get paid more than your fair share. The only BTC pools I know of where this is still possible is Slush and Deepbit. All other pools changed to reward systems where this is no longer possible. There may be a couple more vulnerable ones that don't appear on pool lists.
If you mine Litecoin though, there seems to be a lot of pools using the "proportional" reward system. You can pool hop the hell out of those and get paid way more than with normal mining.