Regularly the most interesting aspect of BrightKite can be found in it's comments, not it's posts. Any chance FriendFeed could import over the comments from these threads and post them in the relevant FF thread as comments.
If those posters don't have a FriendFeed account, their comments could be posted as a guest account with the option for that person to 'reclaim' their comments much like Disqus and Intense Debate.
While I understand this is mostly up to FriendFeed to implement, could this possibly be chased up by BK?
Brightkite is already pretty impressive, but the thing that's really lacking is integration to the outside - obviously I can't really replace Facebook with it, so some sort of integration would be nice. FriendFeed support would also be excellent.