I have a need to persist session data across different pages. A good example of this is the current User profile. With my pre .net apps I used a session variable to store an identifier, and the session data I persist in an XML structure which can be stored in memory or on file (accessed via the session variable identifier). This method is very useful for its transparency and structure, and for the fact that I use XSLT quite a bit, so I can transform directly from this XML.
However I am now researching the ASP.NET methods, and Viewstate looks useful, but I am unsure whether it can be used across an application's session.
Thoughts please.....what is the best approach in the ASP.NET world?