Author’s note: For NaNoWriMo 2012, I wrote a series of short stories loosely connected to the actions of my players on a particular night (and parts of the two days surrounding it). Most of the stories are about NPCs that the PCs saw and/or interacted with. Some are about unknown NPCs connected with known NPCs. At least one is about a previously-unknown NPC who is mistaken for a PC. But the stories are all connected in some way to the storyline.
After spending a month writing 50,000 words about my campaign, I gotta say I feel a lot more grounded in it. I recommend the experience, if you don’t mind being short on laundry and clean dishes.