Quick question.
Does anyone know for a work-arround or fix for my problem:

The issue is that because of the line-height on the paragraph the start and bottom of the paragraph have some white space. In the example given above it’s about 4px. But I do not want to edit my margins on other elements. For example, 40px margin would be 36px.
So does anyone know a good workarround for this?
I did find the css pseudoelement first-line: http://reference.sitepoint.com/css/pseudoelement-firstline
I would approach this problem differently thank looking for a last line pseudo element.
If you are going to have some more content after the paragraph you can style this to move upwards closer to the last line of text.
For an idea of what i mean please see here -> http://jsfiddle.net/Z9LG9/1/
In response to your comment saying “keeping your style sheets as clean as possible” should you not be looking at creating a functional style sheet over a nice looking one? You can always clean up the style sheet after the build phase.
You are going to need to use negative margin for this. There is no way around it that will be cross browser capable.