It worked wonders for the ARToolkit to be connected to the Flash developer community. Maybe it will work for Arduino and hardware hacking as well - using the Netlab toolkit.
A quick rundown of the various physical interfaces I have for sensing information from the real world
In short: Lots. I am going to build a compendium of how to talk to these things from environments I care about, which are mainly Processing, Puredata and then some previously nonexistent time series glue that I might have to write on my own.