Firefox 3 Tips:

Quickies

• For Silly Fun: about:robots - This is just silly fun. In the address bar type "about:robots"
• To Duplicate a tab: Sometimes you want to duplicate a tab. You don't want to lose the tab you are using, but would like to duplicate it in another tab. Just hold the CTRL key and use the mouse to drag the tab to an open area in the tab bar.
• Move to next tab: Ctrl-Tab

Stopping third party cookies

I don't like third party cookies and I recommend stopping them. Third party cookies are those cookies which are not set by the website you visit, but instead set by someone else (a third party). Who would set cookies if you went to Oregonlive.com for example? An advertising aggregator who is paying for advertising on that site and wants to track you for all the various clients they represent. They then have a database and can track your movement across many different sites and put together information collected from various sources.

To stop them choose Tools; Options. Then select privacy and uncheck the Accept third-party cookies option.

The downside to doing this, is that you may have an add-on like bookmark synchronizing, which has to use a cookie sometimes to do their job of collecting your bookmarks for online storage, even though you are on a different site entirely. To allow those web applications to work, you will want to add them as exceptions with ALLOW set for  them.