http://osric.com/wordlock
Given 3 random letters, you try to create a word in as few moves possible by moving up or down in the alphabet one letter at a time. (By a word, I mean a word according to the Scrabble dictionary--many of which I hardly think of as words.) There are two modes, a locked mode and an easy mode, which offer different degrees of difficulty and scoring potential.
It currently lacks the ability to save and compare your scores with other players, but I may add that as time allows.