I stumbled upon this on the Something Awful forums and it looks like it started on Neogaf, but I thought I'd link it here and get some more people involved!
The Final Fantasy V Four Job Fiesta is a community-organized challenge playthrough of Final Fantasy V. As you play through the game, you are randomly assigned 4 jobs, one from each of the crystals; these are the only jobs you are allowed to use for the entire game. As you unlock more jobs in the game, you send a message to the site's twitter account and the account sends back what your new job is. The site keeps a list of every participant and their assigned jobs, so you can see how many people are completing the game.
The other side to this whole thing is that they are also raising money for Child's Play. Some of the donations are pledges from fans of the challenge who pledge money for each player who completes the challenge, or specific donations for specific players who finish.
I don't know how long these people have been organizing this thing, but it looks like they do it yearly. Here is a fun infographic thing on their event from last year.
I've never finished Final Fantasy V before. The furthest I had ever gotten was to the fire crystal, near Karnak. I started this challenge yesterday and am already further than that. I looked at this challenge as a great excuse to finally play through this game. My assigned jobs so far are Thief, Berserker, and Beastmaster.
Check this thing out. I think that it's pretty cool!