clipped from: lifehacker.com   
Check out the following Firefox keyboard shortcuts (some well-known, others not), and before long you'll forget all about the little rodent next to your keyboard.
Opening pages
  • Open link in new window: Shift+Enter
  • Open link in new tab: Ctrl/Cmd+Enter
  • Open address/search in new tab: Alt/Option+Enter
    • Grab bag
  • Caret browsing: F7
  • Refresh: Ctrl/Cmd+R or F5
  • Refresh (override cache): Ctrl/Cmd+F5 or Ctrl/Cmd+Shift+R
  • Switch tabs: Ctrl/Cmd+Tab
  • Select tab (1-9): Ctrl/Cmd+[1-9]
  • Compose email: Ctrl/Cmd+M
  • Spellcheck (with Spellbound extension): Ctrl+Shift+F7
  • Save Entry (with Scribe extension): Ctrl+S
    • And there's so much more!
    Keyconfig allows you to define Firefox shortcuts to your hearts content.

    Download Keyconfig