When I visited ZINGKU today I learned that they have entered in to an agreement to be acquired by Google. All new account activations are on hold and the existing users are given the following message;
"We're Moving to Google
We've entered into an agreement to have Google acquire our Zingku service. If you want to continue with our service, you don't need to do anything; your account and service will be transferred over to Google at the completion of the acquisition.
If you'd rather not maintain your account as a result of the acquisition, no problem. You can choose to discontinue your account any time before October 4, 2007 and your account won't be transferred over to Google. We will delete your account and all information connected to your account. Your user agreements with us will terminate. To discontinue your account, email firstname.lastname@example.org. We will contact you at your registered email address to confirm your deletion request before completing it."