Elizabeth Lane Lawley has this to say about blogs and ideas:
Most of the blogs that I read regularly go well beyond link-and-comment. If they link to an idea du jour, the do so because they have something to add, a new direction to explore. As a result, its not so much an echo effect as it is an opportunity to watch an idea emerge, grow, diverge, expand, be refuted, etc…The interlinking of ideas and content on weblogs, particularly given the linear time-based nature of the form, provides a fascinating window into the evolution of an idea.
This draws a comment by Renee Hopkins:
Link-and-comment blogs are great because by and large they are updated so often (drive-by blogging!) that theres generally a lot of *there* there, in terms of numbers of posts. Even if the poster hasn’t necessarily added much to the original idea, by doing the drive-by thing they are at least pollinating the idea to someone who may have time to comment.
One particularly blog-specific method of building on ideas that I like to read and often use myself is to link to the original citation, add a comment, then use other links to related ideas to start fleshing out the divergent path suggested by the comments. I do this because Im at heart a researcher–though I wouldnt call myself obsessive about it (some have, though!). Research is the way I make sense of the world and ferret out connections. I dont necessarily have to see every single citation of a post before Ill comment on it, but I do like to dig a little into the subject, and/or related subjects, and see if a new connection presents itself–what would you call this, search-blogging?! Except that I generally dont link to the search results, but examine some of them and see if they suggest other maybe more productive search strings. The idea is to see if I can find any connections that might further the conversation around a particular idea.
This also captures the way I tend to look at blogging. It helps in creating a flow of ideas, and at the same time a personal repository of interesting items, which can help in connecting up different strands together.