Quick telephone interview (with some PPC questions, know your stuff!) followed by a group interview in their main office. The group interview was fine, it involved a presentation from the company itself, a pre-prepared presentation from the candidates themselves and a group activity. I won't say what the group activity was because they were clearly very concerned about future candidates finding out, but I'll say that someone else has already mentioned it...
One thing I did not like about this process was that they gave us a schedule in advance (company presentation, individual presentation, group activity) and then signalled that the interview was over. They started talking about wanting to get a couple of extra details from the candidates and then, spontaneously, completely out of the blue, said "Well, while you're here, we've JUST thought that it might be a good idea for you to meet a couple of our guys here for a quick chat one-on-one." I knew this was coming as I'd read other reviews here, but they pretended it was a spur of the moment thing when they had clearly planned it out like that. Why lie? I just don't see the need and think it's very crafty of them.
Otherwise, the company seemed great. They clearly value a good work-life balance and organise lots of activities for staff.