Well, this knife isn't exatly magic, but it is pretty awesome.
I bought this knife after seeing it many times on QVC. Basically what it is a knife with a serated blade. What makes it unique, is that it comes with a guide that screws on the side of the knife. This allows you to slice virually anything evening. You can control the size of the slices by simply adjusting the guide screw.
I was never able to cut anything straight, be it ham, tomatoes, bread, onions or whatever. Now I can. It's so simple, but it works! I was skeptical because things don't always work like it is advertised on TV. This works exactly as advertised. I was really impressed.
Besides a straight slice, you also get a really good knife. I use it sometimes for chopping without the guide. It seems to stay nice and sharp. It has fairly good weight to it and it balances nicely in my hand.
Overall I am very pleased with the Magic Knife and would purchase it again.