mental_floss is now publishing short fiction in conjunction with apt23.com. Check out the first of No Small Tales here. The editors of mental_floss put out an excellent magazine, and submitting a short story to apt23 is a really solidly good idea.
All genres of short fiction for young adults and children — fairytale rewrites, horror, romance, and the ubiquitous six word short-short story — are being sought by TBR Tallboy, deadline June 1st. Tallboy is a new zine that’s going to see the light of day March first, and will have wide distribution among bookish types. Though it’s not a paying market, like the mental_floss, it looks to be a good place to read great stories and get one’s name known; the ‘zine editor is a reviewer and blogger. And a librarian, incidentally.
EDITED TO ADD: Miranda Literary Magazine has put out their 2009 Submission Guidelines. This magazine publishes an online edition, and has a print audience as well.
Prick of the Spindle, a webzine of unique fiction (and weird fairytale retellings), has submission guidelines here.
Strange Horizons, my very favorite speculative fiction ezine pays $.50/word, with a minimum payment of $50 per story. They’re considered a professional market. Another ezine that has some great tales is Beneath Ceaseless Skies — it’s got a very old-school SF feel. Perhaps one of the weirdest and narrowest niche markets for science fiction, ever is … Space Westerns. Some odd but funny stories, and they only pay teensy amounts, but it’s good fun and something for the writing résumé/CV.