I'm the markets coordinator for the Short Mystery Fiction Society, here's our markets list:
I'm one of the editors of Noir Nation: International Journal of Crime Fiction. and we are currently reading for Our second issue. Submission Guidelines at http://noirnation.com.
There are some Flash Fictions in Issue 1 (Which is on sale for 50% off this weekend only http://www.amazon.com/Noir-Nation-International-Journal-ebook/dp/B0...)
Also, forgot to mention, Noir Nation pays.