meebo.com

www.meebo.com is a website where you can easily logs into instant messenger service without having to install any program into the computer. Especially when you're using public computer at cybercafes, schools or universities. It's also a simple solution if office network blocks all IM protocols.

As for me, i had to use meebo whenever i'm running on linux. Yahoo messenger for linux doesn't work. Gaim (another multiple service messenger) runs well but not if i'm behind a proxy server.

Meebo supports messenger service for AIM, Yahoo, GoogleTalk and MSN.