SmartSleep.prefPane let’s you select each select sleep state. Additionaly the new SmartSleep state lets your notebook just sleep while the battery has a high level. If the battery level drops below a certain point ( default is less then 20% or 20 minutes ) it will switch to sleep and hibernate. So you have the best of both worlds.

this looks incredibly useful for airports, hotels, and all those other places we travel that have limited power outlets. even if you don't need to plug in multiple devices yourself, this could let you share an outlet with fellow travelers.