PC Keys
So I found of a way to get beta keys but it's impractical and you might feel bad doing it. This site is "giving" away 30 keys a day. So some people that want to get in can if they show up at the right time.

How?
Sign up for site.
Do the "quest" of liking them on facebook. (Quests may vary?)
Trade points for key when they have some. It was around 4:30 PM Pacific when I saw some.
Just read the comments to judge if they're gone for the day.
Only go here if you're that desperate.

Is it worth it? Only a couple of weekends left of Phase 3 then it's open beta. The last day of Phase 3 is suppose to be around July 15th. So unless you really want to get in on this, maybe not. F sites like that.

PS3Keys
===Old===
They're all gone already.

From Games Radar. There are 1000 keys to be given away.

Also something worth noting at the bottom of the page. "The next play sessions begin on the Fridays of June 28, July 5 and July 12. The FFXIV Beta Phase 3 will end on Sunday, July 14 at 2am PST." I guess closed beta ends in the middle of July. Then we play for keeps.

I got a PS3 key from IGN, free to whoever actually has a PS3.

CJ66-3KNJ-A5RC / RBWU JJZE 9RRS XX83 8FMQ

How to Redeem Your Beta Key

1. Beta keys can be redeemed beginning Saturday, June 29th. Beta will be playable every weekend until July 13th.
2. A Square Enix account is required for accessing the beta. Register here - http://www.square-enix.com/na/account/
3. Connect the PlayStation 3 system to a broadband connection
4. Sign in to your Sony Entertainment Network (SEN) account on PlayStation 3. If you do not have an SEN account, please register for one (more information on www.playstation.com)
5. Choose Account Management>Redeem Codes
6. Select Redeem Promotion Code - this brings up a screen to enter the twelve-digit PS3 code received - (ABCD-EFGH-IJKL). Download FFXIV folder.
7. Go to Games and open the FFXIV:ARR package to begin installation to the PS3 hard drive.
8. Accept terms of license agreement.
9. Follow Setup directions to: Link your Square Enix Account (login and password required). Enter your 20-digit beta registration code (ABCD-EFGH-IJKL-MNOP-QRST) NOTE: BETA REGISTRATION CODE IS CAPITAL SENSITIVE. Please read the Beta Tester Agreement for NDA details before accepting.
10. Link your SEN Username account to your Square Enix Account. This action cannot be undone. Once completed, the FFXIV:ARR PS3 client will be downloaded to your hard drive. This may take a while to download depending on your connection speed.
11. You will need to create or login into your SEA account before entering the beta registration code. You can create your account ahead of time here: http://www.square-enix.com/na/account/

@hargrimm: Thanks a ton, man been trying to get a code all week.

@enns: I got a key for PC using this site, they seem to add 30 keys at around 2:10pm PST and you need to finish a 'quest' on the site by liking their facebook page or some such thing (there's other quests too) after which you can get a key.

There's still 10 left at the time of this post.

where do you go to do the quest for the keys?

@hargrimm: Was that promotion only available on Saturday June 26th? I have a code but it says it is not valid when I try to redeem it.