Okay I've had a strange little inspiration. I am running a DnD game in Eberron, the game will begin in Sharn. Now Sharn is huge, with hundreds of thousands of NPC's, so I had an idea. Why don't some of you play as NPC's in my campaign?! Basically I will give the date, the setting is Sharn, and you can make up whatever type of character you want. You write up a little bio on your character and then say what you're going to do for the date in question. I will of course tell you the results, and then your actions may or may not affect the PC's in my campaign.
For example; One of you decides to play a noble aristocrat in the city. I give the date 14 Therendor(April). You decide that you will on that day throw a grand ball for 50 people, some friends, some nobles you want to schmooze with, and whomever else shows up in time dressed well enough.
I will reply with how it went, what contacts you made during it, maybe a fight broke out. Then we will move on to Therendor 15.
Meanwhile in my campaign when it hits 14 Therendor the PC's may receive an invitation to a certain noble's dinner party, in which someone may pick a fight with them. Or they may even decide to get in good with the guy or girl throwing the party.
Anyway that's my idea. Any takers? If you're interested my campaign begins on Therendor 13, and that would be the first day of play by post play. If you want to play just write up a short bio and what you wish to do for the day. You can use the website for reference on the city of Sharn.