The surprise endings that characterize flash fiction for some can get old. If you go in expecting a surprise, it's less of a surprise. That said, I like the word limits on flash fiction, the challenge to tell a satisfying tale in a short space. Some markets I read are Mysterical-E, DZ Allen's Muzzle Flash, Powder Burn Flash, and Thieves Jargon.
I miss FITG a lot. I love writing flash fiction. I also find it useful for
generating plot ideas for longer pieces. Most of the shorter pieces I wrote for FITG are turning into longer pieces now. Maybe tht's not the point of it, but it works for me. I read the sites already mentioned too.
I like the word limits. I pretty much write whole novels one flash fiction piece at a time. Gerald's right, the Oh Henry endings get old, but as tiny character studies, it's a great form.
I have a novel coming out next year (so, so far away) that is my 2nd with many of the same characters and I'm thinking of writing and posting a bunch of flash fictions with the these characters leading up to publication. Does that seem like a good idea?
I've just started reading flash fiction, and have really only checked out Muzzle Flash so far. I enjoy the form because you can read the work of several writers in a short amount of time and be entertained with minimal time investment. What I find is that when I check out early issues of FF and other online crime fiction sites like Demolition, Thug Lit et al, I'm seeing the names of people who today are getting published in print with longer works and/or who now have books that I want to read. It's clearly a great training ground at the same time it offers writers of all levels of experience to produce work from seeds that might not support a longer story.
As someone starting to write more crime fiction, I like the fact that FF outlets offer more motivation to make good on shorter ideas, and the opportunity to get some feedback and a couple of credits under your belt.
I'll have to check out Gerald's other recommendations.