This week, Gmail added support for downloading your recorded chat logs via IMAP. All of the entries that you can see in your Gmail chats label will now be delivered to your local email client if it is configured to use IMAP.
We have some information about how to set up and use IMAP for Gmail liberation on our dataliberation.org site, but since chat liberation has been requested by many users in the past (both on twitter and our moderator page), here is a screencast that demonstrates this new feature in use.