WordWeb Migh Be The Best
WordWeb is a great dictionary. I own a lot of dictionaries because no one dictionary has it all. But, when it comes to my iPod Touch, WordWeb comes close to doing it all. Attractive interface. Well thought out when it comes to searching a word. Easy to use. Pattern and wild card searches make it very useful for crossword solving. Even has random word searches that emulate the paper dictionary experience of some weird word catching your eye. Highly recommended.
PoCoWordGuy about
WordWeb Dictionary