Forum Moderators: open
domain--name.com
domain-name.com
domainname.com
If you're not expecting traffic where people actually type the domain, having two hyphens is a great way to increase your position in directories since most directories sort alphabetically. I just don't know whether GOOGLE cares or not or what relevance it has.
You can't register a domain starting with a hyphen. As for multiple hyphens, I was really referring to directories that list alphabetically. Having your--domain.com will be higher on an alphabetic list than your-domain.com. It's only an advantage if someone else owns your-domain.com.
I guess it probably wouldn't matter to Google anyway since they don't seem to be focusing much on the directory anymore.