BWR is spot on. I've taken to just shutting the lid, as standby doesn't seem to sip the battery at all and you're ready to go immediately. I have turned on the setting that prompts for the password on resume - I'll take the hit on immediacy for the security benefit.
As BWR says, even when you reboot the CB remembers the tabs and windows you had open, so they all pop back really quickly.
Windows will never, ever seem quick again.