Google Campus: convenient venue but dead area on a saturday night. Tell people to “Bring a bottle + 1”. If you are running a CryptoParty then you are allowed to tell people to do things. Really. A bit. It’s allowed. It’s not against the principles of anarchism at all.
If you’re going to advertise a 6pm start, don’t point people to an auditorium with chairs facing a podium and then purposely leave the podium empty (and the audience bored) until 7pm; instead break the chairs into a circle or put people into a free-form space where they can mingle, ideally with the drinks they’ve brought. If you must use the podium then plan for a warm-up act from 6:30pm.
Learn to delegate. Appoint roles to people.
Pick an on intended audience and stick to it; if you’re aiming to educate newbies then advertise for newbies and plan education around that; if you want geek to speak unto geek then don’t plan on doing introductory talks of the kind where someone asks “How many people know about Tor?” and the entire audience raises its hand.
A ten-minute statement of democratic principles of education may float the boat of the Occupy St Pauls mob, but does not work well for technogeeks. Nor normal people.
Re: the cafeteria sessions, once they got going I think they were good; the geography provided four or five areas where discussions could clearly build around tables, though one should clearly drop the side-tables which literally sidelined themselves.
Also it’s a bit rude to assume that all attendees have to attend all talks and so run from table to table telling everyone to move on at irregular quanta, and then again closing down everything to attend the “lightning” talks. Again I recommend reading http://barcamp.org/w/page/405173/TheRulesOfBarCamp and attending an unconference or two to get a perspective of how to successfully foster organised chaos into education.
Also, overheard: “Lightning talks should be 5 minutes, not 20”. Verb sap.
Also “lightning” is spelt without an E, because they are meant to be fast, like lightning, as opposed to the weight-reduction / illumination-related forms of the word.
Overall: B- would do again. Met some really cool people. And some right weirdoes. Hated the start, mostly liked the finish. Paths of improvement are pretty clear.
I’m not afraid to name names but frankly I think I’ve explained this to the CryptoPartyLond organisation already and so I am merely sharing so that my observations are on the record for other cryptoparties.