Social software

share bookmarks

 * del.icio.us
 * very useful because of accessing your bookmarks from everywhere
 * tags are helpful to find and organize bookmarks
 * del.irio.us
 * similar to del.icio.us, but open source?
 * content is licensed under a Creative Commons license

share photos

 * flickr
 * you can upload photos and pics and tag it
 * recently purchased by yahoo

music
last.fm

networking
not really web services, more remains of the community hype
 * orkut
 * powerd by google
 * openbc
 * business network