Author Chris Robertson has issued a call for submissions to an anthology titled "Delicious Malicious: 100 Tales of Horror". He's looking for horror flash/stories up to 1500 words. Reprints are acceptable. The anthology will be published in both ebook and print editions through Kindle. The deadline is October 31, payment is royalties. You can find all the details here and you'll find more information in the comments.
UPDATE: November 2, 2013 The original call has disappeared and there doesn't seem to be any word on what's happening with submissions.
Hat tip to horrortree.com