1. View a page in FirefoxIt would, of course, be better if the URL was assigned given the page title , but I can live with this. I've not seen it mentioned anywhere, though it's a hard topic to search on. I'm sure it's a general property of the Firefox rich text editor. It's a significant time saver.
2. Click on icon displayed next to URL in the url field.
3. Drag and drop into the editing area. A link appears.
Incidentally, Blogger 2.0 with Firefox's  impressive integrated spell-checking is a qualitative improvement on Blogger 1.0. I've been reluctant to declare that since I've been burned so often by Blogger! Alas, BlogThis! is still stuck in the dark ages; it doesn't support tags. I've got my fingers crossed for BlogThis! 2.0 sometime soon.
 Internet Explorer may use the page title, Microsoft Live Writer uses the page title as does old FrontPage 98 (which I still use - it was a good application then).
 Don't even think of using Safari.