I was messing around tonight and came across a great firefox extension called Better Gmail. This extension enhances Gmail in lots of different ways – like adding saved searches, attachment icons, label colors, keyboard macros, a filter assistant and right-click conversation previews. It also allows for the integration of your calendar and if you use google reader as your blog reader, that is integrated as well.
What I really like is the label colors. Beautiful…It also adds several gmail skins so you can change the look of the interface and allows html in the signatures, which is a must if you want to have creative email sigs.