I found a few great addons for Firefox. They aren't new, just new to me, and already they're helping me with one of my weakest web development points...css.
- Firebug - quoted from the Mozilla web site: "integrates with Firefox to put a wealth of development tools at your fingertips while you browse. You can edit, debug, and monitor CSS, HTML, and JavaScript live in any web page..." Yeah, it does all that, and in a really neat way. For me, it makes css tweaking much easier.
- MeasureIt - "Draw a ruler across any webpage to check the width, height, or alignment of page elements in pixels". A really simple tool, but does its job very efficiently.
- ColorZilla - "Advanced Eyedropper, ColorPicker, Page Zoomer and other colorful goodies". Excellent for picking out those hard-to-describe colors.