Apple is shipping OS X 10.2 "Jaguar". Its most interesting new feature is definitely Rendezvous.

Rendezvous lets ordinary users create an instant network of computers and smart devices just by getting them connected to each other. The computers and devices take over from there, automatically broadcasting and discovering what services each is offering for the use of others. The network could be as simple as two AirPort-equipped PowerBook users sitting in a hotel meeting room miles from the nearest AirPort base station with some large files they need to share. Before Rendezvous, frustration. With Rendezvous, their computers would discover each other making the file sharing completely simple.

Rendezvous makes the automatic discovery of available computer services possible on standard Internet Protocol networks. Based on ZeroConf and the IP standard DNS service, Rendezvous lets you connect to such networks without having to fiddle with settings. You can connect your computers and peripherals together however you like — wirelessly over AirPort and by physical connections such as FireWire or Ethernet. Additionally, Rendezvous provides a service-centric view of the network, so you can quickly tell what’s available.

Update on 2002-07-19: see also Jared White's "Rendezvous: It's Like a Backstage Pass to the Future" and his interview with Stuart Cheshire at Apple and chairman of IETF ZeroConf Working Group.