First off, don't assume you're getting a duplicate content penalty unless you have gotten a specific warning in Google Webmasters Tools. In general, don't use noindex or nofollow tags unless you want the crawler to not index or follow links on that page (which could screw up your internal linking structure).

The answer depends on what kind of sample pages you have and the type of content they contain. Can you provide a bit more detail about these pages, or provide a link? If they are web design samples, you can use lorem ipsum text (Lorem Ipsum - All the facts - Lipsum generator) so you don't have to worry. Remember, your title tag and meta descriptions should be different for each page no matter what. You can also use images for your samples to take content out of the equation altogether.

Yahoo syndicates press releases. They have tens of thousands of duplicate posts. Is Yahoo page 90 of the SERPs?

If you are really worried about it, add the canonical tag or have your webmaster do it. Problem solved.

[DELETED]