How to use Fiddler to debug traffic from Any app (eg. C#/WPF app)

I found the solution at this fiddler2.com page

Why don’t I see traffic sent to
http://localhost or http://127.0.0.1?

Internet Explorer and the .NET Framework are hardcoded not to send
requests for Localhost through any
proxies, and as a proxy, Fiddler will
not receive such traffic.

The simplest workaround is to use your machine name as the hostname
instead of Localhost or 127.0.0.1. So,
for instance, rather than hitting
http://localhost:8081/mytestpage.aspx,
instead visit
http://machinename:8081/mytestpage.aspx.