Since I'm pimping short fiction today, I thought I'd mention this one too.
http://www.lightspeedmagazine.com/
It's just launched and edited by John Jospeh Adams who does some pretty nice anthologies you may have read, a few of them are available at Baen's webscriptions.
You get one free piece of fiction and non-fiction from the issue each week, or you can buy the whole lot straight away in a variety of downloadable formats for $2.99.