I recently stumbled across a very interesting publication called McSweeney's. Now, I'm probably the last person in the world to hear about it. I'm sure. But I was pleasantly enchanted by it, and even submitted a short story to their web edition (the one entitled 'changeling' on this blog, from back in 2004.) We'll see how that goes.
But check it out, take a read.
Also, I really want their circus journal and their 4-issue bundle. Much willpower is going into the fact that I haven't already spent money on them. Willpower! Yaaarrgh.
I also just found out about Ficlets from Joe Scalzi's blog.
It's a collaborative story engine, essentially. Much like telling a story around a camp fire.
You write a little story fragment, and someone picks it up and appends a sequel or prequel, then someone else... then someone else....
Or you do the prequel/sequeling.
It looks like a great deal of fun, and the community seems very open.
I haven't submitted anything yet, but I'm definitely of a mind to.