Could you give me some more details about what you're thinking about? I'm sure MT can be used since there isn't nothing dictating that the system be used for just blogs.
Strip the date, time, title away from an entry and it's just text. Say you don't want text and just want to post photos and receive comments, that can be done as well.
The comments are linked to the particular entry but what you actually put into an entry is very flexible.