There is a .ichat file in ~/Library/Messages/Archive/2012-09-28/ but it only includes the tail end of the conversation.
When you tweet with a location, Twitter stores that location. You can switch location on/off before each Tweet and always have the option to delete your location history. Learn more
There is a .ichat file in ~/Library/Messages/Archive/2012-09-28/ but it only includes the tail end of the conversation.