Is it possible to create an account without a domain name?

For example, could I just have http://www.hostony.com/~username until I want to transfer my domain to this account. I want to get everything working correctly before I move the domain. This should minimize downtime for my site.

Thanks.

Yes. It is possible. You can access your domain in that way (Try our domain- http://209.51.138.26/~hostony/)

To create new account in CPanel I need enter some domain name but later it can be changed easily.

So we can create account for you with test.com (for example) and change it when you give us your real domain name.