Another find service of boringboring.net
OroBaduk... if you can get it to work. The English version is mysteriously terse. (The Korean version explains the entire program, screen by untranslated screen — in Hangul.) Requires Internet Explorer to get registered, click "joining" to take a crack at it. Lost my first game in years (ok, my only game in years!) to some 25 kyu kid named nekopunch in the first half-hour! Obviously, 25 kyu in Japan carries rather more freight than "25 kyu" in the States.