Make Firefox open links in new tabs on a right click

Recently I got a trackball with only two buttons, which means I cannot use a middle click to open a link in a new tab (under Windows). I found it surprising that the developers of Firefox didn't think it would be useful to be able to customize what the mouse buttons do, but I was even more surprised how much I needed to search to find a solution.

Use the InstaClick add-on to make Firefox open a link in a new tab if you right-click it.

Also, visiting about:config and setting browser.search.openintab to true can solve the annoying issue that when you use the search box to start a search, the results replace your current tab.