If you activate the function "Use variables", you can use variables on any sub-page and in all layout settings.
For Example, if you were to write on your website:
"Hello visitor, your IP is [ip]"
your visitor will see something like this:
"Hello visitor, your IP is 126.96.36.199"
You can use following variables:
displays the IP address of your visitor.
displays which internet browser your visitor is using.
displays the url of the sub-page your visitor is currently viewing.
displays the title of the sub-page your visitor is currently viewing.
displays the url of the page your visitor is currently viewing in an input box. Useful, for example, for websites using frame redirections.
displays how many hits your website has had today.
displays how many unique visitors your website has had today.
Also found here http://www.own-free-website.com/help_vars.php