Finding themselves in need of a thermometer that could communicate with the computer, The Cheap Vegetable Gardener resorted to a bit of hacking. They created this PS2 controller thermometer by attaching some thermistors to the analog stick inputs. Each PS2 controller could collect data from up to four thermistors.  There is an auto shutoff feature built into the controller that shuts off the analog signal after a period of non use. To overcome this, they simply taped the L2 button down.

[thanks Shawn]