They say
"A full-featured Yahoo client for LINUX with voice chat and webcam support. Mission: To focus on thorough Y! support on Linux only"

Web Page http://www.phrozensmoke.com/projects/pyvoicechat/install.php#gyachr

The installation on Ubuntu seemed little bit troubling coz the source bz2 files & rpm converted to Debian from there site, complained about some dependency problems..
I got one deb file from internet Its is Here to Download
and this worked fine with Ubuntu Hardy Heron
I was able to login in my yahoo account but the audio and web cam support i vent checked till now coz there where no friends online after midnight ll check and report back soon