Two Ways of Passing HTML5 Web Storage Data to ASP.NET

HTML5 web storage allows you to store data on the client side. However, unlike cookies this data is not passed automatically to the server with every request-response cycle. To pass the data stored in web storage to the server you need to make some programmatic arrangement. Two ways by which such a data transfer can be facilitated are hidden form field and Ajax call. This article explains both of these techniques with an example.

http://www.bipinjoshi.net/articles/217b13c2-7d0f-488d-9a63-1f506516fd57.aspx