Have you ever asked yourself: Where the $&”(% is the RSS Feed Icon in Firefox 4?” I did.
By default the new RSS web feeds subscription button is not visible. To add this to the toolbar ( or navigation tool-bar as it is called in Firefox 4 ) just right-click on the toolbar and select customize. In the customize tool bar window that appears, click and drag the “Subscribe” icon to the desired location. Done.
More Details can be found on technophilia.madharasan.com