After further reading, the Phidget devices seem to communicate through a web SERVICE.
This webSERVICE has a complete API. Libs are available for VB, C++, java, etc, but nothing yet for Ruby.
It's a bit more complex than (what I had originally thought) a simple http scrape, or a socket connection.
To write it in Ruby (ie a gsd/ruby implementation) would require to rewrite the associated API in Ruby.
although this is not IMPOSSIBLE, it is very much a ton of work. Keep in mind, that an API for C++ exists, so it would be a LOT easier to simply create a device in C++ which uses the already existing API.
Now, the kicker:
I'm just starting to learn C++.
Maybe one of the other guys that hang around here could chime in here..