How to intercept HTTP requests and responses of a client machine (like fiddler does)

Question

I thought that the only way to intercept a request is to use a proxy, but fiddler somehow can intercept HTTP requests and responses without configuring anything on any brows

Answer 1

May be running the network interface in promiscuous mode. This is how WireShark is able to monitor network traffic and display it.

More Info: http://en.wikipedia.org/wiki/Promiscuous_mode