I refreshed my knowledge today about sitelinks, the subnav that appears beneath some site’s search results in google. According to google, you can’t force them to appear. It’s been suggested that having too many links in the nav may work against you. Having your navigation in text (as opposed to flash) is required. And you must be the top search result. One site says that your site must be older than 18 months. Other sites agree, age and trust matter. Lastly, here’s a last link, this is all making my head hurt.