I’d like to hook up some sensors to monitor temperature, and energy consumption in my home and I’ve been looking for the cheap options. Â One possibility is the JeeNode kits, which are available in the US from Modern Devices for $22.50.
The US JeeNode combines an 8-bit Atmega328 microcontroller, with a ISM-band 915 Mhz, or 433 MHz radio along with 4 analog or digital I/O ports and misc supporting circuitry.  There are a variety of I/O modules available as well.  If I understand correctly, the JeeNode is compatible with the Arduino ecosystem, so there is a lot of code and hardware expertise to be tapped.
Assembled JeeNode
The JeeNode seems like a great option if you want your sensor nodes to have a bit of intelligence. Â It is cheaper than the combination of some other Arduino plus an XBee wireless shield. Â For my purposes though, an XBee alone may be good enough, since it has enough “intelligence” to be programmed to send readings from its sensor pins back to home-base on a regular interval, or when an interrupt is generated.