Hiya,
There are a couple of ways you could do this. The first being you could use the {homepage} variable combined with {segment} variables to get what you need. That might be a bit messy in your template though but would probably work.
Another way would be using the fetch_current_uri() function from the functions class. You would need to make a simple plugin that would do this for you and it would just fetch the page URI and then spit it out to the page.
fetch_current_uri()
Returns uri for current page.
Class: Functions (FNS)
Description: Returns the full URI for the current page. Occassionally, used in forms when a return location is not set by default.
There is also the tracker array in the session class which would do what you need but only once the person has been to at least one page.
If you can wait until a little later today then I can create a plugin for you if you like unless you know how to create your own?
Hope some of that helps?
Best wishes,
Mark