update 09/2010: http://global.seoul.go.kr/webzine/july/sub09.html
=============================================you can watch korean movies with english subtitles at some theatres in seoul, discussed here on daves. i believe the theatre in yongsan also has subtitles, catering to the military population.
for my own personal reference, since i live close to gangnam: For Cinus Gangnam (Cinus G), go to Gangnam Station, line No. 2, exit 5
dial 02-1330 from your cell phone to get info on movies (or just about anything else), available in english 24/7.
to look up online: movies in seoul, gyeonggido, and other areas here: http://esldaily.org/movies/Korea/
and here's a link for movies in gwangju