Andrew Sullivan has a good article, Why I Blog, in both the online and print versions of The Atlantic. It's a very good description of the blogging experience, a good introduction to the form for those who have never yet dared to jump into these hazardous waters, filled as they are with so many sea monsters.
When he compares the improvisational nature of blog writing with the more deliberate one of writing for print -- exemplified by that very same article -- I discern an interesting point. Writing for print really is different, and you take more time to weigh and balance various factors, reorder them just so. Bloggers just go. You just do it. No time to think and go back and redo it. Besides, what's the point? That sentence was so 1:49 pm, and now it's 1:50!
The implication is that if you want to have the experience of blogging, you just have to keep at it. Don't wait for inspiration, or you'll never blog at all! Get cracking!!