Perhaps Beez can help organize this?
I'm not really the organised type. But I'll throw in my two cents worth.
I took the idea from the scif/fantasy forum's Flash Fiction Challenge. I propose that the simplest thing to do would be to take their formula, and change the XYZs to suit our own needs.
Here's what I mean. They meet at a designated place (the AW chatroom) at a designated time (every Sunday afternoon), a prompt is posted (randomly from a pre-made list) and participants are given a set time (90 minutes from reading the prompt) to write and post their work in SYW, where they are then encouraged to read and comment on each other's result.
As an intersticey community we may well have different requirements for our game than the broader SF/F community does with theirs. Obviously their challenge is geared towards flash fiction, and I don't know if we need to be that narrowly focused. Or it may be that flash fiction is ideal for this sort of activity. We may want more time to work on our pieces, or less. We may not want to do this weekly. At the risk of the whole endevour collapsing in confusion, you guys may decide we don't need such rigid rules and guidelines at all.
Anyways, at its most basic, we'd be deciding on schedule for the challenge (weekly, fortnightly, monthly), a length for each individual challenge (an hour, two hours, 24), and a picker of prompts.
Thoughts?