Anyone can benchmark a Web browser. While the overall validity of any given browser test can vary, in terms of how well it actually indicates a browser's average performance, there are nevertheless a ton of different ways to approximate your browser's rendering speeds. And not only can you run these tools across different versions of a single browser--you can use the benchmarks to compare competing browsers to determine which is really the best combination of speed and features for you.
Of course, since Google's search index now takes site speed into account when generating the prominence of a page's listing on its search results, tools like Speed Tracer have become even more important in the overall Web development picture. And if you're really hardcore, you can use this tool to compare different site iterations across a wide span of time to see just how new improvements and upgrades help or harm your favorite Web apps.
Maximum PC picks one new Chrome extension as its favorite of the week each... week. Have a nifty extension that you can't live without? Twitter David Murphy @acererak with your latest suggestions.