I generally enjoy OS X, but I have a recurring problem with duplicate entries appearing in my "Open With" contextual menu. At any given time I have five instances of Pixelmator, two instances of Xcode, and three instances of TextMate just daring me to choose the correct one. It's relatively simple to fix this problem using Terminal, but I can never remember the proper commands and I know that not everyone is comfortable using Terminal. This led me to create Destroy All Dupes!, a simple application that cleans up your contextual menus in a matter of seconds.
I wrote Destroy All Dupes! to work on my machine (a MacBook Air running 10.8.2), but it should work on just about any system. That said, this software is offered as-is and is used at your own risk. If you can live with those terms, you can download Destroy All Dupes!. If you're uncomfortable with those terms or don't trust an application provided by some yahoo on the Internet, you can usually fix the problem by typing the following into terminal:
cd /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/ ./lsregister -kill -domain local -domain system -domain user