For some reason, our installation of communicator was set not to save any messages by default, but it did save my call history.
Since I don't have any juicy communications at work, I don't have any problem saving everything in communicator. I save those chats for gchat. By the way, administrators of communicator can view your conversations in communicator, so I would be careful when using it. They also control if these settings are available, so you might not be able to change much anyways.
When this option is selected, your chat messages and history will be saved to a folder in Outlook named "Conversation". (Image) Enabling this is very easy. It's done in Communicator, NOT in Outlook.
1. In Communicator go to file, tools, options...
2. Check the box that says "Save my instant message conversations in the Outlook Conversation History folder"
After restarting you will have a folder in Outlook that will save your chats from now on.
Here are my sources, which I'm sure you will find before this site, so I don't even know why I wrote this.