wordpress connected to facebook via wordbook;
wordpress connected to twitter via twitter update;
wordpress connected to live spaces via wp-livesync

facebook has many applications to link twitter, pownce, del.icio.us, etc, together;
there are many other plugins for wordpress to link del.icio.us with facebook; ......

They are all connected. Web 2.0 ? Or, the internet identity intergration:

Hi, I am cail.cn