Tooltips
This is actually quite old, which is good, because it means that it works just fine on any 3.6 or later firefox. I'm not sure how well it fits on this site, but it has a practical application, you can just drop the css on your page and get very nice tooltips with no work at all, and no tag soup either, one tag per tooltip, unless you want formatting in which case it's 2 tags.
It takes care of various edge cases:
- it prevents line breaks in the middle of a span of text with a tooltip
- it accommodates both tooltips longer and shorter than the original text, and makes both look visually pleasing in different ways
- it allows for formatting in tooltips
sorry about the awkward demo, but I mostly just copied and pasted from an old demo.