If you've run a game, you know you've done it or thought about doing it.
If you've played a game, you've had it done to you.
You carefully craft a world to play in (or pick up a pre-crafted one), put all your wheels together, get the cogs tightly fitted and ready for your players to get them in motion, put in a few hornets' nests to kick over, and you're left with the eternal question:
How do I get these people into the same room in the first place?
The village pub is traditional; in a high-fantasy setting, you can't swing a dead cat inside one without hitting half a dozen NPCs just itching lay some questing down on a gang of unsuspecting players. But you can only do it so many times before it becomes a parody of itself, and you set off looking for new and interesting ways to force a bunch of strangers to become involved in resolving the (sometimes lucrative, sometimes not) problems of others.
What's the weirdest/best/worst way to kick off an adventure you've ever used/had inflicted on you?