I have been planying on and off for 3 years and I have noticed a greater number of people who slow play every hand.

Up until recently I didn't reall think there was any reason to slow play.  I was getting frustrated with a player who slow plaed everything.  I fingure they were reading a book or doing their math homework at the same time.  I decided to slow play as well. It turned my game around that day and I lasted longer then I normally do. 

I figure the best time to slow play is when you need to change the game and flow of the cards or when you are on the bubble and need to hang on before the blinds and ante knock you out.

I learned a new skill.  Slow playing has added a new gear to my play: real sloooooow.