Shortcut to search multiple websites in Firefox
Firefox allows you to search a website using a keyboard shortcut. This function is known as quicksearch or "keyword search". MozillaZine Knowledge Base describes how to create quicksearches for a single website.
Each search will open in a new window or tab, depending on your Firefox configuration.
P.S. The keyboard shortcut to jump to the address bar is Ctrl-L in Windows, and ⌘-L on a Mac.