How do I get the silverlight view page name and querstring from silverlight code behind?

Question

VS2010 w/Ria Services & SL4.

I already have my SL app loaded in the browser.

User clicks around to different view pages and I would like to store their current location in a list of "recently visited pages".

To do that, I need to store the view page + any existing querystring key/values.

Ex: here is a real page in my sl app: http://localhost:52878/Default.aspx#/DocSearchShell?CM-Origination

I don't care about anything before the # sign - there are a million ways on google to get the http: // localhost:52878/Default.aspx uri from sl.

What I DO want is the "DocSearchShell?CM-Origination" portion of the querystring - that is what I want to capture and store for the "recently visited pages"

How do I do this from sl4 (.NET 4) code-behind?

Thanks!