Talk to MSN Messenger Using Google Talk

GTalktoVoIP is a service that lets you make voice calls from your Google Talk or Windows Live Messenger (MSN Messenger) client. It even lets you do voice or text chat with Messenger users from your Google Talk - something comparable to the recent Yahoo! Messenger and Windows Live Messenger alignment. There is no registration required - all you have to do is add "service@gtalk2voip.com" to your contact list and interact with it using a command line interface of sorts. Type "HELP" for further details.

Free services include voice mail, voice conference chat, outgoing/incoming SIP calls, etc. Even phone calls to regular phones are supported, but are chargeable.

As of 22nd of September, the Windows Live Messenger/MSN Messenger services are temporarily offline, so keep checking the website for details.