Cheap Atmeg328

I wanted to start using Arduino after talking to a co-worker about his experiences with it.
I sourced the processor and resonator from an ebay seller (why can I get it this way for less than Jaycar?).
So once the parts arrived it was onto my plan to make a X10 garden sprinkler control.
First it was onto finding a library for X10 control. After much research I found on at BroHogan.
This covered the basics of send and receive but I also decided that I wanted temperature sensors. The solution came whilst reading one of the manuals for Heyu. This showed the basic algorithm for temperature sensing. I extended the library to include it and also responding to status requests.