There are couple of ways to hiding URL
1. URL rewriting (given above)
2. ASP.NET routing
with the help of 'HttpApplication.Context.RewritePath' you can re-write URL
see below snippet
.Net Technology: How to hide ASP.Net web page name or .aspx extension[
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3. Using an HttpModule to Perform Extension-Less URL Rewriting with IIS7
4. ISAPIRewrite to enable Extension-less URL Rewriting for IIS5 and IIS6
see below link, it will be helpful to you
ScottGu Blog - Tip/Trick: Url Rewriting with ASP.NET[
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