Check out this PDF which discusses the use of the Xbee radio modules with the PICaxe micro module.  Useful overview of issues with xbee, along with notes on Rob Faludi’s blog.  And though I missed his booth at the Maker Fair, Igor apparently has some interesting experimental applications using the Xbee modules.

I have been thinking for some time of a keychain device which could feed net info to the wearer while they are in the home.  Could as easily be a pin/brooch/ring.  This silly product line makes no sense to me, honestly seems like a hige waste of resources, but at least they have created a zigbee keychain interface, which is very cool.

Perhaps too limited for full-feature ATM controllers, the LPC908 would still be very useful for sub-controllers, for example smart addressable slave devices like RGB LED, servo and light sensor controllers.  The UART is very nice, including 9-bit addressing and even automatic address matching.  1K of memory would almost force one to use assembly, and be very, very limited in program goals, but still.  There are low-cost dev boards and compiler/IDEs.