S2 Games, creator of the online arena game Heroes Of Newerth is planning a 24-hour only open beta period where you will be able to sign up to play the beta without the need for a beta key. This is from their Facebook page.

24 hours of open beta registration coming this week. We will update all our fans with the special URL to get into the HoN beta. Keep your eyes peeled and you can be part of the HoN craze soon enough! :)

I highly suggest you don’t miss out on this great opportunity.

Update: The open beta is now live for 85 hours from now! Get your account by signing up here.