I bought a new programmable thermostat and got ready to install it.
When I removed the old therm I realized it is mounted vertically in a
standard electrical wall box. Well, the new thermostat mounts
horizontaly. I *could* just mount it straight to the drywall, but the
new thermostat I bought won't cover up the entire hole then. Short of
patching the wall I wanted to find an easy solution. I checked the
local True Value and Lowes to see if there was some sort of
cover/adapter plate but found nothing. Does something exist for this
application (and where do I find it) or do I just need to make
something on my own?

Thanks