Architecture :: Allowing Access To Multiple Customers For One User With Url Rewriting

I am currently developing a solution in which the user logs in once and can work on multiple customers at the same time on my site.I've looked at all possible solutions involving sessionid having stored the customerid, to launching a new browser session so i could have multiple sessions for one users etc. I also looked at using cookieless sessions.But the all fail because it's not a simple solution and in my opinion a simple solution is most of the time a good and predictable solution.

Therefore i came up with the idea to use url rewriting(i've seen this used in other applications). When the user opens a customer, i would like to start his url as follows "~/Customers/xxxxxxx/*.aspx" where xxxxxx represents the customerid. and *.aspx represents a complete subset of pages of my site. This would allow me to use a simple technique to use multiple user sessions within a single asp.net session.

Now coming to my problem, I have never done some url rewriting, therefore my questions:

- Is this possible.

- Can i protect all the pages that need a customerid as input(come to think of it, if no customerid in the querystring, redirect to a selection screen would be sufficient).

- How do i adopt all urls used in a sitemap etc in a structured way.