Sorry for the delay in being able to respond to folks, but wanted to make sure I had accurate information before I posted anything.
Dyn has shifted away from offering free DNS, but now offer Pro DNS Trials. Users will be able to sign up for a Pro trial with a credit card and be able to take advantage of all that Pro has to offer for 14 days at no cost to them. At any point in time, users can cancel their trial, and as a thanks for trying it out, they will be able to keep one of their host names for free.
After you have created and confirmed your new account, you will see this screen
giving you options to choose from: At the bottom, you will note that there is a link for signing up for a trial (note that since taking this screen shot the trial period has dropped to 14 days).
Clicking this will start the process of beginning your trial, and creating host names.
Again, you can cancel your trial at any time within 14 days of signing up and still be able to keep a host name for free.
If you get the message that you have already reached your maximum alloted host names (or something like that) and you are currently at zero host names, you will need to visit http://dyn.com/dns/dyndns-pro-free-trial/ and click the "start free trial" button in yellow.
Please note - This only effects new accounts. We have grandfathered 4 million existing users whose accounts will not be effected.
我也是用美国的dyndns. 申請時說免费有2個Hosts.
现在,他们改变了合约。我不得不给$10 US了.
原文如下.
Starting now, if you would like to maintain your free Dyn account, you must log into your account once a month. Failure to do so will result in expiration and loss of your hostname. This activity helps us eliminate hostnames that are no longer needed and/or dormant. Note that an update client will not suffice for this monthly login.
We understand that the possibility of resulting service interruptions may be frustrating, so we are offering a one-time transition upgrade to VIP status (Dyn Pro) for just $10 USD. Under this status, login will not be required and service will remain uninterrupted for an entire year.