Power conditioning. It sounds like a new exercise fad, somewhere between Tae-Bo and step aerobics. But power conditioning actually has a more mundane meaning: A power conditioner is a device that hooks up between an electrical outlet and your electronic equipment to keep the flow of electricity constant. This month's review expands beyond just pure power conditioners; it tosses a higher-end surge protector and a whole slew of uninterruptible power supplies (UPSs) into the mix. What do they all have in common? They share the goal of keeping your computer safely up and running.