I travel with business and would love to be able to keep my structured training plan going. Many Hotel bikes are rubbish, but most have a watts display (yes it is probably very inaccurate, but it is something).
I had the idea of having my iphone/Ipad on a holder and using the camera to read the watts display and Zwift using this.
Its not a mainstream Zwift thing, but I have seen apps that do this with some simple character recognition, you just have to tell them where the key text is. It would be one way of interfacing with most of these hotel bikes (I could see it working on treadmills as well).
Then all I would need is my phone and a phone holder to use zwift on these bikes.