Blogs Use Technorati to find blogs about themes, topics, keywords. Another engine is blogpulse.com that not only lists blogs it also give the trends with how many entries that were entered on a certain day (Trend This). Many times people take quotes from your blog but they may not ask permission or leave a comment. You can search for your name and see who cites you.
Blogging is about conversations - reading what others say and then quoting others and growing knowledge together.