At the risk of repeating, the above advise has been dead on in my experience. If I had a place where I could assure the quality of the power right out of the socket, that would be the way to go. However, living in a New York appartment, where the power is significantly less than stellar, I have found a power conditioner to be a good improvement for as many things as I can plug into it (I am even running a power strip off of the conditioner, and have found that preferable than running it straight out of the wall). It's not uncommon for the lights to flicker from time to time, but with a decent conditoner that gets evened out and not passed along to the equipment. True, its a bandaid where a lack of injury would be preferable--but where the injury is unavoidable it makes for a good addition.
