Probably every reader of this little blog has the dict.cc plugin for OS X’s dictionary app installed. I just realized that you could do a dictionary lookup for words in nearly every OS X application with your fingertips.
Move your mouse cursor to the respective word you would like to look up and touch your track pad with three fingers (like you would do a right click with two fingers). Bam. A small overlay window with the translation and a link to Wikipedia flashes up.