Three paying markets for flash fiction...
Though virtually every conceivable genre and sub-genre is served by
various publications, flash lends itself especially well to
contemporary experimental and speculative fiction, and this is
reflected by the sheer quantity (and quality) of titles currently
available. All those listed below are paying markets.
Untied Shoelaces of the Mind.
http://www.untiedshoelacesofthemind.com/index.php#Submissions
Liquid Imagination.
http://www.liquid-imagination.com/Guidelines.html
Dreams and Nightmares.
http://dreamsandnightmaresmagazine.com/guidelines.htm