Domain Private Registration
 

Is it common place for adult webmasters to register with some sort of private registration service? Or do many just register under a company name?

Both are common practices.

Private registration services have advantages and drawbacks. The obvios benefit is that you (or your company) will not have all your presonal infromation listed for anyone doing a "whois" search.

The drawbacks are that some people may not want to do business with an anonymous person if they can't lookup whois information. For example, I believe "The Hun" does not accept gallery submissions from domains that are registered as private.

And you can't forget... it's more expensive. That along with what JamesAB said, leaves most people with just doing the normal registration from what i've seen.