US Airways sometimes runs its internationally configured business class plans domestically. This is particularly evident between Charlotte and Philadelphia, where they’ll fly their A330, 757, and 767 with envoy seating. Sometimes you will also see flights from Charlotte or Philadelphia to Orlando or Tampa with this seating.
These flights make for excellent upgrades. You get a big comfy sleep. And I probably slept comfortably for 45 minutes of the 1 hour and 15 minute flight I took on one of these 757s from Charlotte to Philadelphia.
Now that is my kind of domestic flying.