I'm buying this Xbee chip.
But it only has 6 ADC pins and I have 12 sensors! Can I multiplex my 12 inputs? How hard is it to do this? I don't want to have to use 2 Xbee modules for power/cost reasons.
You can use a CD4051 8-to-1 analog multiplexer and connect it to one of your analog channels, which will give you a total of 13 channels. You'll need 3 digital outputs to select the active channel on the multiplexer.