I found this thread about Firefox tips and shortcuts very, very useful. If you are a Firefox user, these tips and shortcuts really come in handy while surfing. Here are some of them:

Tip: Double Clicking empty space on the Tab Bar will open a ‘New Tab’

Tip: Middleclick/MouseWheelClick on a Bookmark on your Personal Toolbar will open it up in a New Tab

Tip: MiddleClick/MouseWheel Click on a folder will open all the bookmarks in the folder in a new Tab(s)

Tip: holding down the Shift or Ctrl key when you RightClick to “View Image” or “View Backround Image”will open the image in a New Tab or New Window.

Tip: Unused menus or menu Items can be hidden by using the customizing your userChrome.css stylesheet

Tip: MiddleClick/MouseWheel Click on a Tab will close that Tab.

Tip: Set mutliple Home pages: Tools—->Options—>General and seperate each page with the pipe | symbol
(eg http://forums.mozillazine.org/|http://www.google.com|http://www.yahoo.com

Tip: Clear your Download history to make the download manager more responsive : Tools—->Options—>Privacy

Firefox Mouse Tips

Middle Click
Note: Two-button mouse

For those without middle mouse buttons or mousewheels, ctrl-click will also open new tabs for links, bookmarks, bookmark folders, history items, and toolbar buttons.

Many Laptops mimic the MiddleClick/MouseWheelClick function if you click both right/left pads at the same time.

Clicking both mouse buttons at the same time also mimics the MiddleClick/MouseWheelClick function.

Tabs

MiddleClick/MouseWheel Click on a Tab will close that Tab.

Personal Toolbar

Middleclick/MouseWheelClick on a Bookmark on your Personal Toolbar will open it up in a New Tab

Folders

MiddleClick/MouseWheel Click on a folder will open all the bookmarks in the folder in a new Tab(s)

History

MiddleClick/MouseWheel Click on a History item will open the page in a new Tab.

Back and Forward buttons

MiddleClick/MouseWheel Click on the Back and Forward buttons will open the last/next page in a new Tab.

Home button

MiddleClick/MouseWheel Click on the Home button will open your homepage in a new Tab(s).

Links

MiddleClick/MouseWheel Click on a link will open that link in a new tab.

Quick Google search from Address Bar

1. Go to the “Bookmarks” drop-down menu and select “Manage Bookmarks…”
2. Select “New Bookmark…”
3. A Properties for New Bookmark will appear
4. Under Name, give it a name like, “google search”
5. Under location, put this address, “ttp://google.com/search?q=%s” but with out the quotation marks and put a “h” in front of the “ttp”
6. Under Keyword, put something very simple like the letter “g” (without quotes)
7. Hit OK then you are done.

Once you have done this go to the address bar, type the letter “g” (without quotes), hit the spacebar and type any word you want to search for like “afterdawn”, hit enter and you have done a quick search. For example type, “g afterdawn”. press enter and a google search for afterdawn will turn up. Very Easy and Cool. Have Fun!

Go here for a complete list of Firefox tips and shortcuts!