If you have set the default feed reader for Firefox, you no longer have an option to preview a feed before adding it to your feed reader of choice. This can be a little frustrating when trying to quickly look at a feed without actually adding it.

For those of you that are unfamiliar with the way RSS works in Firefox, notice the orange RSS icon in the address bar

When you click on that icon, you'll be taken to a page previewing the feed. You might want to notice that this preview page does not show the full feed, just previews of each post.

You'll notice the checkbox for "Always use Google Reader to subscribe to feeds". Firefox also supports bloglines and yahoo as well.

You can select this checkbox to set the default feed reader for the first time. If you want to change it later, you will need to open Tools \ Options, and click on the Feeds tab.

You can set the default application to handle feeds here. If you want to reset back to the default, you can change the radio button to "Show me a preview and ask me which Feed Reader to use".

Note: If you are a serious RSS user, you should use Google Reader.