Hi all! 
I'd like to know.. What would be the best way to communicate to one Arduino to another? I need this to be simple to do and work long-range.
I was wondering if it'd be possible to use radio frequency? I don't really want to purchase anything, certainly anything expensive.
I only need to send values from one Arduino to another, just like serial communication.
Something such as '1' or '24' etc... Haha.
Thanks guys!
It depends on what you call long range. Meters or miles?
XBees have 100m range line-of-sight for the Series 1 type.