ok when i click on buy now on on toribash.com, it shows the three options. so what does it mean by keys? why the different options? is this per month or something? I'm quite confused as to what I would buy two or three of... can someone please explain these things to me?

one key=one registered version of toribash. If your just buying it for yourself, click the 19.95 one. If for more people, click on the corresponding one. And it is not a monthly fee.

Yeah, it just means that like... if you have a family member that wants to play too, you can buy 2 at the same time for cheaper then it would be to buy two for 19.95, same thing with 3