Well i am not sure if this could be done but couldent there be a page where you open up and enter your username and it shows your username date registerd and other stuff, then there will be a link to it so you can use it?

No its the users own signiture that the forum generates them 

I think he means like this

http://www.dkpsigs.com/

I think what you mean is making a dynamic forum signature based on your forum's members post counts. There is a way to do that on your own with a PHP script, I remember doing one for SMC, and I could write a tutorial but it wouldn't work on any free host that I know of. Do you mean something like the one in my sig including the specific member's name and his/her postcount?