WritingFix is, as Keith Barrett would say, a bit of fun. It provides a series of 'interactive writing prompts' designed to get the little grey cells turning, and with just a few clicks of the mouse you might be prompted to write about 'a magician', 'a dark cellar' and 'a wild animal is following your character'. It's supported by some good articles on idea generation, so if you're feeling stumped give it a try.

WritingFix