Firefox 3.1 is set to be a big release including Private Browsing and TraceMonkey (much faster javascript). If you’re interested in getting a sneak preview beta 3 has just been made available and is usually a good time to get involved.

Have a look at the changelog before you upgrade, and then hit up the download.

While I was there I also noticed Firefox has a Tips and Tricks section with some pretty useful information if this is a first move for you, or even for more advanced users:

Now you can use Web-based protocol handlers to provide quick access to your favorite Web applications. For example, you can set Firefox up so clicking on a mailto: link on any site will open a new message in your preferred webmail provider rather than your computer’s default mail program

Popularity: 8% [?]