imo.im is one of the best things I've seen lately. After first being surprised by the number of applications in the Chrome Web Store I was amazed to find an application that could almost fully replace my desktop Pidgin! A chat client that runs in a browser and supports most major chat services is a must everywhere I go now.
I'd expect the sync to pick up the installed applications and make them available anywhere I run Chrome browser. This, firewall permitting, would enable contacting my friends, dispersed across various chat networks.