The recessed thing sounds like a good idea actually, first off, it'd be more stable than just nailed to the wall, but also, if you surrounded it with the wall insulation, it'd be kept at a nice moderate temp. If you wanted to get extra fancy, you could do like SuperChuck said, and put a picture (say a picture of you, smoking a cigar), over it, and mount one of those remote himidity gauges near it, so it'd look like a thermostat for the AC. I'm not sure why one would goto such lengths to hide his 'dor, but it sounds like a cool idea nonetheless.