Never used anything beside Windows Messenger? Then it's time to try out some alternatives! There are several of them, for example Digsby, Miranda and Trillian, but I just love Pidgin.

Absolutely irresistible mascot!
I have a confession to make: When I was considering my switch to Ubuntu I was mostly concerned if I was able to let go of Windows Live Messenger. I was blinded by it's flashiness. It was pretty and even a bit customizable. But I decided I can live few months without it and along came Ubuntu and Pidgin.
I didn't like Pidgin at first. I quite desperately tried to seek for a prettier alternative but there were none. I had no other choice than to stick with Pidgin. But it didn't took long until my eyes opened. It wasn't flashy, it was classy. It wasn't lame, it was user friendly. And eventually I fell in love with it.
There are dozens of reasons why I think Pidgin is better than Windows Live Messenger, but here are the most important ones in my opinion:
1. Pidgin is better because there is no ads
I was always bothered by the ads on Live Messenger. They were annoying and simply everywhere. And I found it quite unethical that there were ads for alcoholic beverages. There are kids using Live Messenger too and they should keep that in mind too when choosing advertisements.
2. Pidgin is better because it doesn't have any super duper cool but useless extra features
Did I ever used any of the Live Messenger extra features? I'm afraid I did not. Though I did accidentally click the nudge button for several times! I only want to talk with my friends, not to bother them with all those strange activities that Live Messenger offers. Don't get this wrong, Pidgin is very versatile too and it has some cool features as well.
3. Pidgin is better because it's a multi-protocol client
Live Messenger allows you to log in with one MSN account at one time. That's so uncool. I have two active MSN accounts and I want to use them seamlessly in the same time. And with Pidgin that is possible. And I could be using these too: AIM, Bonjour, Gadu-Gadu, Google Talk, Groupwise, ICQ, IRC, MySpaceIM, QQ, SILC, SIMPLE, Sametime, XMPP, Yahoo! and Zephyr. Pretty awesome, right?
GO GET PIDGIN (runs on all Windows and UNIX platforms)
NB: Pidgin may crash down occasionally on Windows Vista, but it works perfectly fine on XP and Ubuntu.

Absolutely irresistible mascot!
I have a confession to make: When I was considering my switch to Ubuntu I was mostly concerned if I was able to let go of Windows Live Messenger. I was blinded by it's flashiness. It was pretty and even a bit customizable. But I decided I can live few months without it and along came Ubuntu and Pidgin.
I didn't like Pidgin at first. I quite desperately tried to seek for a prettier alternative but there were none. I had no other choice than to stick with Pidgin. But it didn't took long until my eyes opened. It wasn't flashy, it was classy. It wasn't lame, it was user friendly. And eventually I fell in love with it.
There are dozens of reasons why I think Pidgin is better than Windows Live Messenger, but here are the most important ones in my opinion:
1. Pidgin is better because there is no ads
I was always bothered by the ads on Live Messenger. They were annoying and simply everywhere. And I found it quite unethical that there were ads for alcoholic beverages. There are kids using Live Messenger too and they should keep that in mind too when choosing advertisements.
2. Pidgin is better because it doesn't have any super duper cool but useless extra features
Did I ever used any of the Live Messenger extra features? I'm afraid I did not. Though I did accidentally click the nudge button for several times! I only want to talk with my friends, not to bother them with all those strange activities that Live Messenger offers. Don't get this wrong, Pidgin is very versatile too and it has some cool features as well.
3. Pidgin is better because it's a multi-protocol client
Live Messenger allows you to log in with one MSN account at one time. That's so uncool. I have two active MSN accounts and I want to use them seamlessly in the same time. And with Pidgin that is possible. And I could be using these too: AIM, Bonjour, Gadu-Gadu, Google Talk, Groupwise, ICQ, IRC, MySpaceIM, QQ, SILC, SIMPLE, Sametime, XMPP, Yahoo! and Zephyr. Pretty awesome, right?
GO GET PIDGIN (runs on all Windows and UNIX platforms)
NB: Pidgin may crash down occasionally on Windows Vista, but it works perfectly fine on XP and Ubuntu.