Clover has always been useful (and Cenqua has always been generous with licenses for open source projects), but I finally got around to installing their Eclipse Plugin. It's not perfect, but it is simple and it does work. My old procedure was the run my tests using Ant to build the code coverage, then switch back and forth from a web browser to my source code. This is much, much easier (though the markers for lines that have not executed are a bit too subtle ... I'd prefer a change in background color, as with the HTML report).
Meanwhile, it's time to fill in some of gaps in my code coverage test suite!