A couple of weeks ago, Compass Airlines began daily service into LAX from Kansas City. While the destination is not new (Frontier and Southwest also serve this route), the carrier is. Compass was a regional partner of Northwest (flying as Northwest Airlink), and is now flying for Delta (as Delta Connection) out of Minneapolis-St. Paul. They use Embraer E-175s configured for 76 passengers. This brings the number of Delta Connection operators at LAX up to three; besides Compass, we also have Mesaba and SkyWest in Delta colors.
This is the first Continental B737-500 I've seen wearing the United name. Continental uses the B735 to Leon, Mexico, a route that was previously flown by Mexicana. Curiously, Continental opted to install winglets on their -500s, while our other B735 operator, Southwest, has not.
AeroMexico has recently brought in this B737, which they added to their fleet earlier this year. A lease aircraft (notice the US registration), it formerly flew for Air Berlin and Hamburg International. Included here because of the nonstandard paint on the tail; compare to this shot from the B737 Spotter's Guide: