I'm, Steve Harris, I teach games design at Anglia Ruskin University in Cambridge, UK http://www.anglia.ac.uk. I'm using phidgets (mainly accelerometers and RFID readers) to help students develop novel user interfaces for their games which they are developing in Unreal Development Kit http://www.udk.com
I have had to create my own C++ DLL, based on the phidget sample files, and then link this to UnrealScript (the scripting language in the Unreal engine) using a DLLBind. I've posted a full tutorial on my website http://www.designforplay.net in the Tutorials section. This will show you how to create a DLL which will communicate with the Unreal Engine. The tutorial will walk you through how to add code to communicate with an accelerometer. Adding other phidgets is relatively easy once you have been through the process once.
I have also posted some demo videos of the interfaces students are creating using phidgets and UDK.
It would be great to hear from anyone who is, or is interested in, using phidgets in UDK.