Guildford Library kindly provided a room, some power sockets and tables and the rest of it was cobbled together by the organisers. The main hurdle we came across was monitors which we eventually got round by using the ample supply of library laptops, connected to the Pis via Ethernet. There is a good tutorial here if you are keen to try it. The library also provided USB peripherals but all the Pis were provided by the organisers.
Beyond the 6 laptops we had, the desperate scrabble for screens included using an ancient CRT screen found in a corner (had composite input though (and even a built in VHS player!)) plus two ancient projectors again with only composite inputs. The CRT screen worked a treat, we spent most of the day trying to get the overscan settings of the projector correct which I think was eventually abandoned.
There was plenty to do with about 8-10 Pis to tinker with. There was a robot arm, a string of 150 neopixels, Sonic pi setup, sense hat plus plenty of Scratch and Minecraft goodies to get on with.
Maplin turned up and kindly donated a Fuze board, many thanks to them, we will definitely be tinkering with this in years to come!
We took a time lapse of the whole jam using a Raspberry Pi camera which is on YouTube:
It was ultimately a success as you can see from the general hubub and the people who stuck around for almost the full day. There was a mix of people looking for help, those looking to dabble in something new, experimentation with physical computing (robot arm, LED lights), a youngster who hacked a Scratch game so every time he lost a life he gained 100 and plenty of Minecrafters.