Found one of 'em http://ffxiv.zam.com/forum.html?game=268&mid=128271283675079473&page=1
Beta codes distributed through Final Fantasy XIV fan sites – including approximately 500 handed out through ZAM.com – will become invalid unless they are registered by the end of the current phase of beta testing.
The current phase of testing, Phase 3, is scheduled to end at 5 p.m. PDT on Wednesday, Aug. 25.
People who are already registered and playing in the beta will receive emails in their Square Enix Accounts. The emails will contain new codes that can be redeemed in the same fashion as previous codes.
The current codes will become invalid because the codes are changing for the launch of the open beta.
We will keep you updated on this issue when we have something new to report. Until then, spread the word to register your beta codes before it’s too late!