"Real World Sensors for Commodity Desktop Computers - Comparison of Networking Strategies and Local Connections"
Compare Bluetooth vs Zigbee vs Ethernet vs Firmata vs "Serial" USB vs "real" USB.
I guess Arduino cheats, by making most things look like serial ports, but it could be one of several datapoints. I claim that the portability you gain by using a low common denominator (like serial) is interesting (and a bit depressing), for example. The whole subject of very powerful desktop PCs that have such difficulty relating to real-world stuff is ... annoying.