Each state has its own specific requirements for a will to be considered valid. Don't asume that you can just write/videotape something on your own. It may not hold water in court. I'm an attorney but do not specialize in estate planning. I cannot advise on do-it-yourself programs, as I don't know anything about them. However, should you go that route, find out how many witnesses your state requires. It may be 2 or 3. I would have one extra witness over the required number, just in case. Also, make sure that each witness is a DISINTERESTED witness, i.e. not entitled to inherit anything under the will OR under state inheritance laws. Basically, exclude all relatives. Also, the witnesses must know that they are signing a will.
Personally, I would get an attorney. This way your mind is at ease that all drafting formalities have been fulfilled. Its not very expensive to do a simple will. Call around.