The icon used for the duckduckgo is cool...with a duck head wearing a bow tie. But i feel that the icon should be upgraded to something that pulls people towards it. There are lots of opensource community help, that have been pouring out icons, which seem to have been dropped straight from heaven, so much beautiful than the traditional windows and mac icons....GNU/Linux icons are far better and really add the eye-candy.
The first time i saw duckduckgo i neglected it thinking that its some children's game...game for 3-6 years old. Only after many months, that i came to know that its a search engine.
The icon is very cool and nice but i think you should have some serious icon! something that will make people want to know about it. something that people are pulled towards, like ants are pulled towards sugar.
This is just my thinking. I don't know what hidden meaning the icon has but i feel it should be more cool like other opensource projects have..