They have been around for 40+ years. It is a hair clipper that is attached to a vacuum. A friend of mine has one and she cuts her own hair and her dogs. She loves it. You see them advertised on TV.
www.flowbee.com is the website. I do remember them from commercials - I don't know Meg - if you say someone you know uses it for their dog and it works, maybe.....have you seen their dog?
As far as for people - I would have to think that you wouldn't be able to do much with regards to really styling your hair, it would only be one length.
There's a similar product called "Robocut" (or something like that) that I recall one doodle breeder (not on here) used for her dogs. I think it worked okay!
I have the Robocut and it works great. Its just like the Flowbee just a different brand. I got it online. Its great because I don't like to shave all of her hair off like the groomer does. You can cut as little as a half an inch off. It just sucks the hair up the vacuum hose tube and you put different attachments on for the amount you want to trim off. It comes with an instructional dvd for dog cuts.