outlineattribute -- essentially a
borderattribute that does not allocate any space / screen estate. Very convenient for focus visualization, and the like. (I wonder if the Fujitsu-Siemens Activy Media Center boxes I twiddle with at work employ this for their rather unstylish red focus borders. I have to try that out.)
In finding this property -- actually by asking the Firefox Document Inspector what the borders around a focused
<a>tag came from in an old home page of mine came from -- I also stumbled upon a nice bookmarklet for showing page structure using CSS outlines rather than borders, as was the case with the classical bookmarklet for this same purpose.
I also felt I should leave a friendly "thanks for all the fish" kind of note, as Will somehow managed to before me, but even after making myself an account (to supposedly be able to comment), I was not rewarded with any comment form. I figure you might for once save yourself the trouble, in case you feel the same way. (...Or perhaps pay tribute by posting a blog entry of your own. ;-)