This is my fourth draft, and it is now out of date. I wrote my fifth draft 2014-04-05. You can always find the latest version at purl.org/net/tbc/blog/about.)
Not everything I want to write is appropriate for this little Web log. I use my accounts at StumbleUpon, Kuro5hin, and MetaFilter to reach larger audiences.
I use StumbleUpon (SU) like a "hyperblog." Whenever I visit a Web page that I find interesting enough to comment on, I do it: one click on the toolbar tells SU that I like the site, another click opens a form where I can write a comment about it (just a sentence or two). That's all I need. When I first wrote about SU tagging hadn't been invented. That changed about a year ago at SU, and that clinched it for me. It has everything I want now. I have stopped using my del.icio.us account, even though I used to like it. Since the last time I wrote about how I blog, SU has become my favorite tool. I have been using it more than everything else combined.
Occasionally I get an idea for a substantial story that I think would be of widespread interest. I submit those stories to Kuro5hin (for the benefit of my friends who've never heard of it, it's pronounced "corrosion," a pun on "Rusty," the Web site owner's name, and just K5 for short). My bylines at K5 give me the right (in my opinion) to call myself an independent journalist. It has a couple of limitations with regard to blogging, though: (1) it has to be a good target for discussion (K5 emphasizes discussion), and (2) it has to get past the voters. It's been a while since I submitted a new one, but my K5 stories are still online in the archive. I haven't used my Kuro5hin diary recently, either. In the past I've used it for things that I wanted to share widely (at least some people read the Kuro5hin diary section :), while I wouldn't expect anyone to bother to link here. Sometimes I just feel like trying to start a discussion (K5 threading is the best I've found).
I joined MetaFilter (MeFi for short) only a few months after joining K5, but I've lost interest. It's not great at discussion because it doesn't allow threading, and it's all mindless link propagation (a section that K5 keeps separate from more original writing). Still, I hate to give it up because matthowie kicked me off once and I had to beg and grovel to get my membership reinstated. (Don't we all tend to value more the things we've had to work to keep? :) See my MeFi threads and my MeFi comments on other threads.
I use this personal blog for more ego-centric stuff. Here I have a place where no one bothers me about promoting my own stuff. I first thought I would log my activity across the Web as I do it, but that's what I now use tbc.stumbleupon.com for. Presently my blog is hosted at livejournal.com, but I set up a PURL that I publicize: purl.org/net/tbc/blog.
I have one other major outlet for writing. The Wikipedia is a sort of blogging tool. Opinion is forbidden in Wikipedia stories, but it's an ideal tool for following developments to things that can be defined as encyclopedia entries. Blogging wasn't popular the day the Twin Towers were hit. I followed the 9/11 story at Wikipedia as it developed minute by minute (and created the first draft of Osama bin Laden article). I have made many contributions there. I consider it to be related to blogging because it's so easy to add content and because you can read it sort of like a blog via the Recent Changes view. It even has a way to register comments (where opinion is not discouraged) -- just click on the "discussion" link at the top of every Wikipedia article.
Having said all that, in the time before I had this blog I set up a few QuickTopics -- the "instant discussion space." That tool, too, has its place. It's so preposterously easy that I expect I'll continue to make use of it.
Addendum 2006-09-16. One other activity that counts as blogging: I use LibraryThing to share the list of my favorite books. That's also my preferred repository for book reviews.