I really like to plurk! I also think this microblogging/life-stream app has huge potential in mining/ aggregating information. Microblogging is successful because it serves the low-road, all the people who are not willing to spend hours on writing articles, but have the need to express themselves on the web. By plurking a life-stream of short sentences with simple preselected verbs, you can stay in touch easily with your friends, and expressing your current mood and thoughts. The processing of this short sentences via NLP or similiar, might lead to interesting applications.