Mac OS X v10.4, 10.5, 10.6: How to look up ".local" hostnames via both Bonjour and standard DNS

The Multicast DNS feature of Bonjour allows devices on a local network to connect to each other without a separate DNS server by using the ".local" domain, as described in this article. This advanced article explains how to make your Mac look up host names ending in ".local" using both Multicast DNS and standard Unicast DNS using the name servers specified in the Network pane of System Preferences. Some private networks also use ".local" domains for hosts registered with their internal DNS server, even though it is not a valid top-level domain on the public Internet. If your Mac is connected to such a network, you may want it to look up host names that end in ".local" by using Unicast DNS to speak to a DNS server, the same way that it looks up host names such as "www.apple.com" on the Internet.