After reading some folks in ubuntu, my eyes point to something i know before, but i just found out what is it for. it’s called “bonjour”, i often heard bonjour from macintosh, but still don’t what it can do. After googling i found a nice explanation of bonjour all about

Bonjour, formerly Rendezvous, is Apple Inc.’s trade name for its implementation of Zeroconf, a service discovery protocol used in Apple’s Mac OS X operating system from version 10.2 onwards. Intended for use on local area networks, Bonjour uses multicast Domain Name System service records to locate devices such as printers, as well as other computers, and the services that those devices offer.

http://en.wikipedia.org/wiki/Bonjour_(software)

for simple, if you ever use the “net send *” for sending a message via LAN, bonjour do almost the same, except rather only a text message, bonjour can be use for other such audio, or even a video.

Well, the good news is, since pidgin 2.2.*, they included bonjour in their standard protocol, so it’s not hard if you want to chat through local network instead of for example yahoo. it’s easy and fast to setup although it’s doesn’t have many features in it, what lack is video conference or text conference, but it’s quite useful when you doesn’t have any internet connection, since it worked it local network only. Well happy trying