Routing to 127.0.0.1 is dumb for this reason, especially since you may be running something on port 80.

Unless you have something listening on the ports that doesn't respond or a firewall that is dropping packets on the loopback interface, "connection refused" is returned right away.

Here is the 0.0.0.0 version: http://someonewhocares.org/hosts/zero/

Years ago I maintained a popular ad blocking hosts file. I got a lot of complaints when I switched from 127.0.0.1 to 0.0.0.0. Some TCPIP stacks just didn't like it. Others had little webservers running on 127.0.0.1 that quickly served up 404's for speed or black jpegs to make things pretty. Someone out there maintained a little httpd for windows that did just that. If it saw a GET for blahblah.jpg it would serve up a black graphic of some random size. It sure beat the default FF or IE error message.

Honestly, there's no need for this stuff in the age of browser based ad blocking. I gave up on it when I saw how easy it was to write rules and wildcards in ad block plus. Interest in it fell. I'm surprised to see one still maintained.