I was glancing at digi-key again, and I found a sexy RF transceiver that has a RTC, temperature, battery monitor, and even a signal meter... two of them, for $20.
I'm just a bit scared.. it says it uses UART connection, but I'm not finding much code! I did find this:
And they have a LOW power consumption.. something like ~25ma when transmitting, up to 50 meters at 250kb/s.
I want to interface them to me Arduino's, but just not sure what kind of commands I'll be needing to send to get it poppin!