Thanks to Lifehacker (once again) for a very handy tip. If you’re like me, you use the search box in FireFox regularly, and in doing so I usually open a new tab for the results, this hack sets search results to automatically open in a new tab:
Type about:config into the address bar, and then put the following into the filter box: browser.search.openintab. Double-click the value to change it to true.
Simple, yet totally useful.