Fred Wilson is blogging about Firefox extensions today, specifically on the benefits of adding features to the content (the actual webpages) versus adding functionality to the chrome (new toolbars, sidebars, etc.).
He uses Mahalo Follow as an example to make the case for in-content data being more valuable than in-chrome, making me feel all warm and fuzzy inside. Of course, that feeling might also be due to the microwaved kiwifruit I just ate.