If people want to organize themselves in the comments to this post, to make such an index, that would be terrific and super-helpful!
oulangi is working to organize requests, and eventually fics, on del.icio.us. More info coming soon to this space on how you can help.
Thanks to thefannishwaldo, a collection-space has been set up on An Archive of Our Own (aka AOOO) - you can find it here. If you have an AOOO account, you can add a story to the Help_Haiti collection by clicking here, then clicking on Post New Story.
If you don't have an AOOO account and want one, comment here on this thread, and we'll try to get you an account within the next few days. I have one invitation myself, and I'll give it to the first Lightning Round offeror who replies to this post with I'll take it! in the subject. Just link me to your Lightning Round thread.
Obviously, use of AOOO is entirely optional and up to the Offeror and the Fic Recipient. Right now, because AOOO only hosts fic, it's also limited to stories only.
Lastly, thanks to glockgal who donated an LJ gift cert so the comm is now "paid" and ad-free!