If two Americans are arriving two hours apart (on CX and AA) and need to arrive in Gangnam together, where should the first one kill the extra time and where should we meet? Neither of us has arranged a local cellphone yet, does the airport have good wifi?

Any recommendations would be appreciated, I've only visited Seoul once before and left the airport as quickly as possible.

Went thru this just last month ... ICN arrivals all empty into the main terminal on the same (lower) level thru doors marked A,B,C,D ... rather typical international arrivals layout and very clear. You can't completely predict which hall a flight will use for baggage and immigration (my wife and I both on DL flites from US, one in thru C, one in thru D) so a seating spot just outside whichever one you decide is a safe way to go, they're separated by about 50 yards. There is a Kraze Burger just outside the D door, which was our spot. There's also a BIG Karaoke stage (!) between C and D doors. At that spot an escalator to the upper level -- all open atrium (view of everything and everybody) so up and sit down on the benches there would be good, too.

Wifi thruout the terminal was my experience.

Go to the basement and try the jjimjilbang (Korean sauna) while you wait. Just really throw yourself into the Korean experience. There's free wifi throughout the airport (can't verify the basement jjimjilbang, though).

Otherwise, it's just a bunch of random cafes and restaurants. If you walk over to the train station building, you can ice skate and even go to CGV cinema.

oh and my bad. I didn't see the "two hours" part. You should do whatever you want, and then just go find their arrivals door and stand in front of it. Easy.

Highly recommend the sauna. It is called Spa on Air down in B1 level. Even if to just take a hot shower. You can tell your friend to make his way there after arrival and then meet inside the lounge area.

Another easy place to meet would be the McDonalds on the arrival level. It is in the middle of the airport and hard to miss.

The Burger King or McDonalds or Kraze Burger (my favorite) would all be good.Usually so, but my wife arrived a few hours after I did recently and her exit was not at the expected doorway. I would be safe and pick an easy-to-find spot and have a snack (BTW, the Korean food court on the lower level isn't well known by most travellers, but is very cheap).

As above post mentioned, there are several fast food franchises around ICN. It's prob the easiest rendezvous spot as most ppl know Mcdonald, burger king and KFC.