Two years ago I "stealthed" my big ugly Davis 6372http://www.wxforum.net/index.php?topic=8067.0
It was pretty good, but the wires still ran outside, secured by cable ties and metallic duct tape.
I did a 2.0 version last week when the pool boy came by to open.
I drilled a half inch hole at the point where ladder inserted into concrete. Another smaller hole on vertical for my OS sensor. And another half inch hole near bottom of ladder.
I pulled a string through the holes. Then pulled the os sensor first then the davis sensor. I was tight getting the RJ connector through safely. I orginally planned on pulling the probe end as it was just under half inch, but there was no way to get the angle to pull the wire. The two sensors exit at bottom of ladder 2 feet down. The rj heading towards xmitter comes out, runs in the channel I cut into the concrete 2 years ago to the xmitter hidden in the cedars. In the end I have completly hidden wires. Yay.