So I've been doing some work on what I'm going to be delivering for this year's Bristol Festival of Literature and have found this very useful! http://www.thewritingplatform.com/2013/02/immersive-writing-lab-series-how-to-create-a-storyworld/
So what makes a good Logline? for me, for the purposes I'm working on for this year, it would need to be open enough to spark good creativity as well as having just the right amount of boundaries and restrictions, necessity being the mother of invention.
As a collaborative platform then pretty much all of the other parts of this will need to be open - the writers filling in as they go along probably
More info when I'm allowed to start publicising this!
Also stumbled (or rather was guided to it by Angry Robot) across this http://booksworn.com/ which is an intriguing concept - 16 authors get together to create a blog...