Jistory is a javascript hack to fix the AJAX history problem. It current only works in FireFox (although a work around does exist for IE). Jistory utalizes the anchor tag (#) to create virtual urls. There are many scripts like this, Jistory is only intended to be a lightweight and easy implimentation of the technique.
I personally like to use #/ before my urls as that gives the apearance of a folder.
Click on the links below to see an example.