Among other features that Opera has is the right-click Paste and Go option when you paste a link into the address bar. Firefox does not have this feature and I missed it dearly. Im lazy and I think its to much work to paste the link into the address bar and hit enter or push a button afterwards to load the new site.
Paste and Go is a simple Firefox add-on which adds the functionality know from Opera to Firefox. It adds the paste and go function to the right-click menu when your mouse hovers above the address bar. It adds similar functionality to the search bar where the right-click menu entry is called paste and search.
Last but not least you can use a keyboard shortcut for the same effect. In Windows and Unix it is Control + SHIFT + V, on Mac COMMAND + SHIFT + V.
Some users are reporting that the newest version of the plugin caused errors while using the keyboard navigation. This is no problem for me because Im not using keyboard navigation at all but it might be for some of you who do. You better dont install the extension if you use or need the feature.