Yea. . .making your way as a foreigner onto the Korean side of the internet is really a pain sometimes.
Like holdfast said, a lot of the big sites like Naver and Cyworld require you to send your id/passport pic as well as some other info in order to verify your identity. And there are quite a few other sites that don't even have an option for non-koreans or people w/o a krn SSN to register. It really is a little much. . .
But alas, if you have enough Korean friends you want to keep in contact with you almost have no choice (talk about peer pressure) but to go through this process. I registered at both Naver and Cyworld and both were rather frustrating, particularly Cyworld. . .i was flat out denied by them the 1st two(three??) times that i tried because of. . .hmm. . .i can't even remember the reason anymore but the emails are somewhere in my gmail archive. All of this AFTER i had sent them my precious info! (mind you i have a squeaky clean record
) so i was more than a bit confused. Anyway, I tried to send them emails in my broken Krn to complain but they didn't respond until I got one of my krn friends to send them an email as well, after which everything was fixed promptly the next day -_-. Comparitively, Naver went much smoother but was still a bit of a hassle.
This was all a loOong while back, so i'm hoping things are smoother now, even if you have to send all that info still.
Despite my complaining it is really awesome having accounts on these sites. I've been able to keep up with all my friends, have my own blog (i admit i don't use it much tho), and I'm part of a bunch of interesting Cyworld/Naver groups. It all makes me feel. . .well, like more korean haha...or at least more like a part of the community and that has done a lot towards keeping me motivated to master the language.
I would say you guys still try to register, especially in your case ziggy, you can laugh at your krn friends reaction when you say "here is my cyworld address..." and they ask "US cyworld?" then you reply shocked "WHAT?!? there is a US version of cyworld?!" hehehe~