My all-time favorite is Jasper’s Google Reader subscribe. What does it do?
Every blog, almost every news site, and many other web sites provide RSS feeds. They are a handy thing but some sites make it hard to find the corresponding link or don’t display it at all. The only chance to find the link would be to browse the source code of the page. Scanning the code while you’re in front of a computer? Ridiculous! Let’s use the machine and that’s what this script does.
It looks for links containing the strings “rss”, “atom”, or “rdf” and displays a small icon at the top right of your browser:
If you hover the mouse cursor over the icon all found feeds will be displayed:
As you see not only the main feed is found but also the comment feed and possible others. With this script installed you can simply click on this icon and subscribe to feeds without frantically scanning the page.