Mechanical only n cash games on-line... Someone already said it... New faces jump in and out all the time. Getting cute will only cost you more than it will make you.
Tourneys can be different in the later stages assuming you have been playing with some of the same guys for hours at a time.
I will try and attack tilters when I have a nothing hand and they have a short stack. (nothing like the feeling of taking down a pot with an all-in bet and flashing 7-2....)
Freaks them all right out.