By the nature of the setting, the NPCs are easy to contact and are often a decently intimate part of your character's daily life. If you would like to thread with an NPC in your own posts because you feel that it's relevant, because your characters are contacting them, or because you'd like to have a dramatic encounter.
Just comment to this post (with a link, if you'd like) and let us know the situation. We'll bring the NPCs where they are most needed.