I have been very happy with Radiotronix modules. They are not cheap, but they are as close to wires as you can get. I have used the EWD900 series with PICS, and they are a bit difficult to set up, but very versitile. The Wi.232DTSs need no programming, and I set up a wireless link that transfered 100 Kbytes of data at 115200 baud ,1200 feet flawlessly, with little pigtail antennas! I am guessing with a couple of Yagis, a range of 1 mile would be a breeze. They run about $25.- each for ten of them, but I believe they are worth every penny.

Hope this helps,
Ron