You can use multiple free chat software when talking to your friends, but it seems that only a few are worth installing. So, here are the ones that got into my list:

1. NimBuzz - Free Calls, Chat, Messaging and more on your Nokia N8. Nimbuzz is the first in my list because it has a better interface and allows me to send pics more facile on Yahoo Messenger. Also features Facebook chat.

2. Fring - You can connect multiple chat clients. It's not that great when it comes to the interface, but it's the only software that let me make a video call. It uses it's one video call server.

3. Skype - You know what Skype is all about. What you don't know is that it does not have support for video calling on Symbian platform. That means you can only make audio calls on your Nokia N8. Maybe they will do something about this in the future, but for now, it's on the 3rd place in my list.