A great little tool that i have found for firefox is the Load Time Analyzer . As a web developer often you are often trying to increase the speed on the rendering of data. Well this is where this firefox add-on comes in.
In a nutshell it graphs off all of the events that occur when the page is being rendered. You can set specific events to be displayed or all of them.
Anyhow, definately a must have for developers. Download it here .
Unfortunately it’s currently not available for firefox v3… doh!