It took me a little while to find this, so I thought I'd share. You can access BonJour (nee Rendezvous) discovery services from the command line by using the command dns-sd in 10.4, or mDNS in 10.3. There doesn't appear to be a man page for mDNS in 10.3, but it appears that the options for dns-sd, favored in 10.4, work just the same for either command (and in fact the man page for mDNSis present in 10.4).
For example, to view all of the ssh shares on Bonjour-enabled computers, try this in the Terminal (replace dns-sd with mDNS if you're on 10.3): You should receive a list of workstations that are broadcasting ssh services via Bonjour. Don't forget that you need to replace the spaces with hyphens and add a .local prefix when trying to connect. For example, to ssh to Macintosh HD found this way, you need to use ssh Macintosh-HD.local. To view AFP shares (maybe AppleTalk isn't turned on?), try this one: This page lists more of the potential services you might be able to find. And, as always, you can read the man pages for more help (in 10.4, at least) -- man dns-sd has a few pages of content.