Vista RTM goes into sleep state
 

Unlike that, the sleep function wakes up the computer in the matter of seconds. It takes five to seven seconds to have your machine back on the feet. You can revoke a bunch of programs. It takes twenty-five seconds to put the programs to sleep and some seven to wake them up again.

You can put the machine to sleep and wander off to enjoy the silence of your home until you need it again. It won't take more then seven seconds to get it back on its feet and start working, as if it was turned on all the time. It beats hibernate and beats the booting the machine and works great if not perfectly.