The face recognition tech was really interesting. It's 99.9% accurate which is better than humans! Runs into challenges once inside an exhibition though - I asked about exhibitors using to know who is approaching their stand which could help them optimise their approach, use their best people etc. However, the same restrictions that apply to photographing a group versus an individual without permission come into play. I suspect there will have to be an opt in as part of registration to get around that. Also discussed in time the face recognition linking to security checks...a whole can of worms there to overcome but would be great to really know who is in the room!
On a lighter note, I came home with relatively low tech but always welcome giveaways!