Here's some general information:
--American, America West, Continental, Delta, Frontier, Laker, Northwest, Southwest.
--Frontier, Metrojet, TWA, USAirways.
Pier E (International Terminal)
--Aer Lingus, Air Canada/Air Ontario, Air Jamaica, British Airways,Ghana Airways, Icelandair, and charter flights (such as ATA).
For specific assignments, take a look at the end of the following page:
Mind you, this is out of date information (I'm pretty sure it doesn't include the Pier B expansion for Southwest, because they have many more gates there than just 6), but it should give you an idea of what airline's where there.
Hope that helps!