April 23 is a day dedicated to posting free fiction (or other artistic content) on the Internet -- the backlash to a disparaging comment the then-VP of the Science Fiction and Fantasy Writers Association made about people who post their work for free online. A little history behind that controversy is here, along with discussion of why giving your work away online can be a Good Thing, even if your goal is to be paid for it and support a world where authors can be paid well for their creativity.
According to Wikipedia, April 23 is also World Book and Copyright Day, which is a neat piece of synchronicity, if perhaps also a source of unintentional irony.
Elsewhere on Livejournal, ipstp collects links from people who are releasing free material in honor of the day. My own modest contribution is episode #53 of my serialized fantasy novel "Legend of Hero," which you can also read from the beginning.
(April 22, of course, was Earth Day: hence the post icon. I didn't get a chance to do anything special for it this year, but I'm glad it's gotten such popular traction.)