This is where it gets tricky, because search is a task, not a goal.
Jeff Bezos and John Battelle help explain this better:
[Bezos uses] "discovery" as an umbrella term which incorporates search. I think in the end when I use the word "search" I really mean "discovery" as Jeff uses it. What's discovery? Well, much more in the book, but in the end, it's search plus what happens when the network finds things for *you* - based on what it knows of you, your actions, and your inferred intent.
Last week I watched Steve Jobs explain Technorati's advantage over Google - he was talking about Safari's RSS search, but Technorati searches millions of blogs for you within minutes of them updating, not just the RSS feeds you have already subscribed to.
But again, searching for keywords is missing the point.
The great thing about weblogs is when you discover someone. Someone who makes sense to you, or someone who surprises you with a viewpoint you hadn't thought of. Once you have found them you can subscribe to their feeds and see how they can keep inspiring or surprising you.
You can even start a blog, link to them, and join the conversation,
The continuity of viewpoint within a blog is key - you can see more about them than just the one comment, and you can keep discovering and growing with them. Conversely, being aware that what you are writing is 'on your permanent record' means that you write more carefully for a blog than for an email.
Blogcritics sent me a CD to review - Call Off the Search by Katie Melua. Rosie loved it, but the title song sums up what I'm getting at here: "Now that I've found you I'll call off the search."
Blogging is about what you discover, not about what you search for.
How you can follow the conversations and make new discoveries is what I'm working on. [updated 2014 - original Steve Jobs link was broken 5 times over by Apple: it linked to homepage.mac.com (Which they killed) hosting a Quicktime reference movie (which they killed) to a streaming Quicktime movie (which they killed) of a Steve Jobs keynote (which is now offline) explaining Safari RSS search (Which they killed).