Eight hour layover in Inchon Airport...

I will be in the Inchon Airport for 8 hours...on a flight layover... Is there any chance of going into the City and getting back in time for my flight...I arrive around 830AM...and the flight is around 545pm...

So long as you start heading back to the airport at around 2pm you should be able to make your flight. Going by trains from Insadong to the airport took me almost 2 hours, and involved several connections.