EBuddy
Ebuddy web messenger (former e-messenger) is a web instant messaging that let you chat with msn, aim, yahoo, gtalk and myspace even if you are blocked by firewall
http://www.ebuddy.com/
JMessenger
Branded instant messenger offers online private messaging service, dating, community, gaming and business. private instant messenger offering businesses to run their own private web based instant messenger as well as download messenger
http://www.jmessenger.com/
WebMessenger
WebMessenger
http://webmessenger.blitzaffe.com/