One site multiple domains hurt my SEO?

[SirLucius]

I am building a site and I have one domain registered with Moniker and another with GoDaddy. The domain registered with Moniker has the DNS pointing to the webhost. I want the domain registered with GoDaddy to lead to the same site, but I don't want to be penalized by the search engines for having two domains leading to the same site. The Moniker domain has the search terms I want; while the GoDaddy domain is more marketable and I wish to use it on business cards and print advertising. How can I best set-up these domains to not get penalized by the search engines?

Do I setup a 301 redirect with GoDaddy domain?
Do I change the DNS to the webhost with GoDaddy doman?
Do I setup a 301 redirect and change the webhost with the GoDaddy domain?

Thanks,

[tazsolmarketing]

setup a 301 redirect change the webhost with GoDaddy domain