The service currently supports
3. AIM / ICQ
4. Google Talk
5. My Space
When you select the Facebook option, you are provided with the Login with Facebook button which first logs you on to FB and gets your permission for providing access to IMO with your personal details.
A good site if you would like to access your multiple IM accounts online without using an IM client and without registering on the site for the service.
Currently it is free. The GUI is very basic but good enough for a free service. New chat windows opened are not cascaded and are visble in horizontal order.