(Changing subject line, since this is clearly about Oxford, not London!)
> We discussed Oxford last year, and the only qualm was accessibility.
> I'm still reasonably sanguine about this - it's a 1h40 bus ride from
> London, 1h on the train, regular buses from the London airports, etc
> etc.
I'm going to contact a few coach companies and see if we can put on
our own transport. It would be more convenient, probably cheaper (I'm
hoping they'll do it for free or at least heavily discounted, I've
known coach companies do sponsorship deals for university events,
hopefully they'll do the same for us) and possibly quicker (I'm not
sure how direct the public coaches are). An hour and a half on a coach
with a bunch of other Wikimedians shouldn't put anyone off coming.