Highest-profile UK sites running WP/WPMU

What’s the most famous British company or organisation using WordPress?

I’m a new media consultant based in southern England, doing a lot of work in government and broadcasting. I’d love to be able to use WordPress in more projects, but a lot of the clients I speak to are conservatively minded. They like what they see, but would be happier to commit if they felt other ‘big names’ had also done so.

So far it’s been tricky to find UK-specific examples of large companies and organisations basing their work solely or largely on WordPress. So I thought I’d ask those who almost certainly know best… ?? Individual bloggers don’t count, unless they’re someone famous for something else.

I’ll start the ball rolling with:

– funky printers Moo.com. Certainly their website’s blog is powered by WP… and I read somewhere that WP underpins their entire site.

– multi-award-winning social activists MySociety

Er, that’s all I got. Please help! I’m lining up some work with a few very big-name clients, and I really don’t want to have to do it all in Typepad again!