Firefox 3.1 uses a new JavaScript engine called TraceMonkey to increase browsing speed. However this is not enabled by default and thus most users are not able to utilize the benefits this script.
How to enable TraceMonkey?:
Type about:config in the Firefox address bar and click 'I'll be careful, I promise' to the following warning:
In the filter field type: javascript.options.jit.content
Double click on it to change the boolean value from false to true
Restart Firefox to...
