For some large installs of Mac computers, it would be ideal to not have so many Bonjour advertisements. This would include advertising services like Screen Sharing and File Sharing.
To stop the Bonjour advertising, you’d want to disable mDNSResponder. However, doing so in the past would also disable DNS on your Mac.
Luckily, Apple has built in (and documented) the proper way to disable mDNSResponder in Snow Leopard. It involves adding a line to the mdnsresponder.plist.
For instructions see this Apple Support page. Take note to read thru the whole article before starting.