I stumbled across the Writer's Digest article "101 Best Websites for Writers" and have been happily wasting time exploring. Here are some of the ones I liked for inspiration:
Easy Street Prompts has a daily photo or video which gets you thinking of story ideas immediately. A story of careless bike riding monkey- kids, an old black and white photo of people waiting on a stoop, etc.
First 50 Words presents a fifty word paragraph and then gives you an assignment to write. The current one asks about your favorite movie.
The Story Starter has 2.6 billion first sentences loaded in their database. You hit a button and a random sentence comes up. It is fun just reading all the different first sentences.
If you're stuck, or in need of inspiration, check out these links.