[SageRaven]

There's a unix utility called "surfraw" that does this. I don't know if it support DDG yet, but it's very cool.

[bct]

All surfraw seems to do is generate the URL for the search and opens it in a browser. Disappointing :(

[TallGuyShort]

I just got it installed and quite like it. It may not give you interactive search capabilities, but it DOES support DuckDuckGo, and the other "elvi" are quite handy. I now have a quick way of instantly opening Lisp, Java and other language docs in the terminal, and jumping straight to wikipedia articles in w3m.