Firefox: SelectionSK is a Firefox extension that offers language translations, highlighting, and multi-engine search to
Chrome only: One of the many things new users learn about Chrome, fairly quickly, is that right-clicking on images doesn't offer a "Properties" option. Get back your simple image information window with the Image Properties Context Menu extension. More »
And as you can see in the screenshot, there's an extension that does a nice job of integrating the contents of your bookmarks bar. Install "Bookmark list in context menu" and you've got two-click access to your favorite sites. It's a nice alternative to the horizontal bookmark bar, especially on smaller screens where every pixel counts. As its author points out, it's also a handy way to open bookmarks in full screen mode -- when there are no toolbars to click on.