Is there any good way of truncating text with plain HTML and CSS, so that dynamic content can fit in a fixed-width-and-height layout?

I've been truncating server-side by logical width (i.e. a blindly-guessed number of characters), but since a 'w' is wider than an 'i' this tends to be suboptimal, and also requires me to re-guess (and keep tweaking) the number of characters for every fixed width. Ideally the truncation would happen in the browser, which knows the physical width of the rendered text.

I've found that IE has a text-overflow: ellipsis property that does exactly what I want, but I need this to be cross-browser. This property seems to be (somewhat?) standard but isn't supported by Firefox. I've found various workarounds based on overflow: hidden, but they either don't display an ellipsis (I want the user to know the content was truncated), or display it all the time (even if the content wasn't truncated).

Does anyone have a good way of fitting dynamic text in a fixed layout, or is server-side truncation by logical width as good as I'm going to get for now?