Following the clear and simple instructions at No Fancy Name, I've added 'expandable post' functionality to my blog. What's especially good about this hack (compared to others I've seen) is that the 'continue reading' link only appears if there really is more to read.
So now when I write a hideously long and boring post, I can make it so that only the first couple paragraphs (or whatever) clutter my main page, with the rest of it hidden away on the individual post page.
Then again, some people might prefer being able to read the whole thing from the main page without having to bother clicking through at all. Hmmm. Well, I'll do a quick poll: Who prefers long posts to be represented on the main page by a brief excerpt only, and who prefers the whole thing to appear?
Update: I've gone ahead and excerpted my longer posts, so now I can fit twice as many entries on the main page. For those who prefer to read several full posts together on one big page, just use the monthly archives (e.g. here) instead.