I want to make a counter that with every unqiue visitor it goes up .2 but only up to 100 then goes to 1.2 1.4 , etc

heres an example of something I think you're looking for.

http://inobscuro.com/tutorials/read/30/

You're going to need to log the ip of every visitor into a table, and compare that with every page hit, then use another table for recording page hit history or however you want to do it. If you have any problems, let me know and I'll be able to help out.