A friend is meeting her cousins at the Seattle airport, then they are driving to a family wedding. They are arriving within an hour of each other, airlines are Southwest, American, Continental and United. She wants to know where they should arrange to meet?

Arriving passengers will all end up at the baggage claim area. There are restaurants and lounges in the airport of course, but I don't think they are in the arrival area or in a location that non-passengers would be allowed to go to.

I think you may get a good response by going to www.flyertalk.com and selecting "Miles and Points" in the center box. Then go down to Alaska Airlines - a very informative group of posters.

AA and UA bag claims are at opposite ends of the airport. If you don't mind the UA people making a longish walk of it (maybe 5-7 min.) there's a large seating area next on the bag claim level near the "A" gates. There are a couple of airplanes suspended on cables from the ceiling, with tables below. It's at the extreme south end (AA, British, international arrivals) of the airport.

I was just there last week, and I can tell you the only place to meet is baggage

You could decamp over to the nice lodge at the Doubletree (and call their shuttle to pick you up). Much nicer than baggage, in my opinion, and they even have free computers you can use.

All arriving passengers end up coming on the escalator that puts you in the large baggage claim hall. That's where everyone will end up. Beyond that, your only choice is leaving the airport.