penders - 11:25 pm on Nov 30, 2011 (gmt 0)

lucy24's solution is a good alternative and can be achieved with the same/similar markup. Float the <span>.

Both have good browser support AFAIK. Although IE6 might be a problem.

ps would be able to force the span in the above (my example) to take up the remaining text of the paragraph without writing extra characters?

Not sure what you mean? ...Creating the <span> with JavaScript?