USB port

[Ronald Zellner]

I was reading the comments about Phidgets and externals and started wondering about being able to use the USB port to connect to special devices- mechanical switches, etc. for use with children with special needs,
Is there a source of information about how to connect and read such things?  Transducers for things like strain gauges, thermo detection, etc. would also be useful.
Would appreciate it if someone knows where to find information related to this or if you have developed any such interfaces for LiveCode.
Thans,
Ron