I'll update this list of landside airline lounges (outside security) as contributions are provided, and even add airlines if offered.

CO Presidents Club

• BOS (until the November 2007 CO move from Terminal C to Terminal A)
• LGA
• SFO

NW WorldClub

• DCA
• JFK (Terminal 4 "Sky Lounge" -- joint use, NW-operated)

DL Crown Room Club

• PHL (Upper level, Terminal E -- until the 31 May 2006 DL move to Terminal A - East) See Post #20, infra.
• SFO (Mezzanine level at the ticket counter)

AS Board Room

• None

US Airways Club

• LAS (former America West Club)

UA Red Carpet Club

• LGA

LH Senator Lounge

• TXL (Tegel Airport, Berlin)
• CGN (Köln Bonn Airport, Cologne)

AA Admirals Club

• JFK (Terminal 8, Concourse B, 3rd Floor -- above int'l ticket lobby)
• MIA (Concourse E, 5th Floor)
• PHL (Terminal A - East, next to Thos. Cook)
• FRA (upstairs, between Terminals C and B)