I have a trip to South Korea coming up and I'm getting some conflicting information.

I have two guidebooks (2006 and 2008) which say don't drink the tap water.
I have a third guidebook and saw a TV show which both claimed the tap water is fine.

All four said that bottled water is plentiful and cheap wherever you go, which based on my previous travels, is usually a sign that you shouldn't drink the local stuff.

Does anyone know for sure?