How to remove PROTOCOL from URI

You can use this the System.Uri class like this:

System.Uri uri = new Uri("http://stackoverflow.com/search?q=something");
string uriWithoutScheme = uri.Host + uri.PathAndQuery + uri.Fragment;

This will give you stackoverflow.com/search?q=something

Edit: this also works for about:blank :-)

The best (and to me most beautiful) way is to use the Uri class for parsing the string to an absolute URI and then use the GetComponents method with the correct UriComponents enumeration to remove the scheme:

Uri uri;
if (Uri.TryCreate("http://stackoverflow.com/...", UriKind.Absolute, out uri))
{
    return uri.GetComponents(UriComponents.AbsoluteUri &~ UriComponents.Scheme, UriFormat.UriEscaped);
}

For further reference: the UriComponents enumeration is a decorated with the FlagsAttribute, so bitwise operations (eg. & and |) can be used on it. In this case the &~ removes the bits for UriComponents.Scheme from UriComponents.AbsoluteUri using the AND operator in combination with the bitwise complement operator.