If you just want to chat with peeps on yahoo, or aim, or any other IM protocol I would install gaim it's a nice multi protocol IM client. To install in software in debian just open up a terminal type su root <enter your root passwd and hit enter> type apt-get install gaim and teh rest is done for you. While your at it if you don't have it already get synaptic, same deal apt-get install synaptic. then you can use synaptic to install virtually any debian pkg known to man. If this is no good and you have your heart set on using ymessenger I'll take a look to see if I can get it going and write up a tutorial for you. Let me know how you make out.