One of the time saving tools we've developed is our Domain import tool. Quite simply, you tell the tool what domain to import and it goes and grabs all the current DNS records for that domain and imports them into Zerigo, ready for your review.
This does require the remote nameserver to agree to send your domain's information. If it won't do it by default, it's usually possible to tell that server to allow such a request from Zerigo.
Another convenient tool is our Domain upload tool. Simply tell the system what domain to build and upload a BIND-style domain file.
Our system will immediately parse the file, pulling out all of the host records, and then build the new domain for you, ready to be double-checked. It's a fast and easy way to build a new domain with data from an outside source.