This is a great tip to get you on your way to make Duckduckgo your standard search engine!
Why do you want to do this? Because you just very well might be a 34 old female with herpes.
With the update to Safari 6 either with or without Mountain Lion the omnibar is now a standard feature, this means that the SIMBL plugin I had been using earlier is unnecessary. While that seems like a win on the one hand, with the depreciation of the Safari Omnibar SIMBL plugin goes its ability to make use of other search engines.Fear not, there is a solution to this dilema! Arne Martin has created an extension to provide that very functionality and it’s called Safari Keyword Search 2.0.
via DuckDuckGo in Safari 6.0\s Omnibar — The Real Steven Teskey.