After reading an interesting writeup on it on Download Squad, I've been working with an alternative browser that you may very well have never heard of: Sleipnir. It's a very popular browser in Japan, from a company called Fenrir. The reason it got my attention is it's an extremely customizable browser, and it allows you to choose whether you want to use Firefox's Gecko rendering engine or Internet Explorer's. If you, as I do, primarily work in Firefox but keep Internet Explorer on hand when you run into trouble such as rendering problems, this browser presents an interesting solution.