I can explain a few things about how the galerie-photo medium and large format photography group group was formed.
At the beginnig there is a private initiative by Henri Peyre from Nîmes to create un 2000 a French web site dedicated to large format photography . Then a discussion forum was created in 2001 and is now continuing with more than 4000 registered readers.
Very soon the exchanges on the forum were followed by informal regional meetings were people gathered with their equipement and pictures.
We also have organised a visit to Arca Swiss one of the few manufacturers of LF cameras in Europe.
One of our group members, Henri Gaud is both a professional photographer and publisher, the boss of Éditions Gaud. After our first workshop in Nîmes in 2004 he decided to organise the next meeting in 2006 with an ambitiious photographic project at the Fontfroide Abbey (near Narbonne in the south of France, close to Spain.)
So this something special to our group since H. Gaud had worked for decades in cistercian abbeys on professional assignements with LF cameras, he was a good friend of Fontfroide's owners, the d'Andocque family who owns the abbey since one century.
So very naturally the 2006 conference was held at Fontfroide abbey, H.G. got the permits for taking LF photographs by a group and he published the book.
Well no need to have a publisher in your LF-UK group to organise something substantial !
I believe that informal regional one-day meetings are very important.
There is very little to organise, what is needed is a place where equipment and images can be displayed for a few hours without risk of getting wet. Not that I suspect that the British Isles could be more wet than the Continent, but for example at our last meeting in March in the East of France (Vosges, near Gerardmer) we had a continuous heavy snowfall for 3 days before the meeting, so we coud re-enact "Clearing Winter Storm" !
An easy way to organise this is of course a typical French restaurant where lunch duration is hardly shorter than 2 hours, usually the group can stay chatting for a substantial part of the afternoon inside the restaurant after lunch, but any other place is perfectly OK, even a fish 'n chips restaurant would be OK if the group is allowed to chat and display LF cameras, books, slides, prints... for one hour or two

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Now for the future meetings
We have an informal meeting this Saturday in Arc-et-Senans (Franche-Comté) where Raymond Depardon has an exhibit of pictures taken with a 8x10" camera (or should I say a 10x8" ? or a 20x25, since Britain is now metric)
The next event will take place in Montreux, Vaud, Switzerland with a summer photographic exhibition organised by the Centre Culturel Maison Visinand.
http://galeriegf.free.fr/montreux_2007/index.htm
In September we'll have a worshop in Montreux organised by Pierre Stringa, program to be announced.
For 2008 the new conference is already scheduled for October and will take place in Bourges, in the centre of France, in connection with a LF photo work on Noirlac abbey. Noirlac abbey is the property of the local governement, Département du Cher.
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So after this long intriduction, among many open questions, the question of a cross-Channel, joint meeting can be discussed...
All the best !