One feature that has helped Cyworld take off is "wave riding." It works like this: When you're reading posts on bulletin boards or looking at photo files, you can click on the name of someone who has added a remark or photo you find interesting and you'll be transported to that person's digital room. If you like the art or music, you can introduce yourself and put in a request to become a "cybuddy." If accepted, you can use your buddy's goodies -- from art to photos -- on your own page. The chain of wave-riding visits creates communities on the Net, which often develop into clubs of common interest in the real world: clubs for fishing, bike riding, and going to jazz performances, among others.