Web Instant Messenger Websites
Web messenger for the web, access instant messaging from anywhere whether you are behind a firewall, at at school, at work and from any other location.
ILoveIM.com Web-based Instant Messenger Service for MSN, Yahoo, AIM, GTalk and MySpace messenger networks
AirAIM, the only web messenger that lets you access AIM from absolutely anywhere.
Web Telegram Client: This Telegram client enables you to access Telegram directly from your browser.