in reply to Perl Phone Call Screening Device
Just tossing out another idea.
Your post made me immediately think of Arduino, which is based on the concept of "open-source" hardware. You can probably find more info at http://www.arduino.cc/ and http://arduino.org/.
Also, you can join the mailing list of hardware.pm.org, which is headed up by Robert Blackwell. At YAPC::NA 2012, Robert setup some Arduinos in the hardware hackathon. I didn't make it to the hardware hackathon sessions myself. However, I heard from some folks who did go say that they had initially thought programming hardware would be difficult for them but found Robert's demos very easy to setup and program. Anyways, if you join that mailing list, I'm sure you could some help with Arduinos or other Perl/hardware solutions for this or other things. For example, Robert gave a talk about using Arduinos to getting your doorbell to send you a text message.