I've been phoning around a few academic and research libraries in London today - specifically, the University of London Library (Senate House), the British Library and the London Library. The people I've spoken to have been tremendously helpful, even if the result has been disappointing. The British Library will allow access to their collection, although attendees to a Library Storm would need to get a pass, which requires ID. The same is true for Senate House, which said that the passes would be £5 a person, and they'd need an attendee list up front, otherwise there would be delays getting in. The London Library said that passes would be £10 a person, and there is no area for collaborative, non-quiet work.
I'm going to do some e-mail followup this evening with them, and then am planning to phone a few more libraries tomorrow. I've got a very useful book called
Book Lovers' London (published by Metro Publications) which contains a list of bookshops, specialist and academic libraries. I'm planning to focus on the academic libraries - Greenwich, Westminster, Metropolitan and the various U. of L. college libraries. I'm trying to find libraries with wide collections. There are lots and lots of interesting libraries covering everything from on everything from cricket through Charles Dickens. That said, I might phone the Imperial War Museum library and the Lambeth Palace library, since war and religion cover a fairly significant amount of human history.

I'm also planning to invite non-CZ people to get involved. I know lots of people within geeky circles in London, and am trying to get people interested who aren't already CZ authors. It'd be helpful if we were to have a speedy approval process for people at Library Storms, so they could turn up on the day and start writing without having to wait long for approval. Basically, this would mean having Constables online during the event. They will already have to prove their identity to get access to the library, so we could have it so that myself or other authors could expedite their membership.
When phoning the libraries I generally say something broadly along the following lines:
I'm calling as a contributing author to an online encyclopedia project called Citizendium - which is a new, expert-driven project similar in scope to Wikipedia - and am looking at the possibility of running a research day in London, where ten to twenty people would work together on research to improve and write new articles for Citizendium. I'm wondering whether it would be possible for [library name] to allow us access as a group to the collection.
Right, off to take the dogs for a walk, then time to write some e-mails, then maybe write some more pages for CZ.