I launched my site some time ago, and have been successful in getting my website listed on DMOZ, the Open Directory Project. Now when I do a search on Google that brings up my site in the search results, Google shows the DMOZ snippet as the description, and not my meta description or a snippet of content from my page. Why is this?
The "snippet" (the short description that appears below the title of your page in the search results) is dependant on what the user searched on. So for example, if the DMOZ description of your site mentions Tom Cruise but your page is now more about Angelina Jolie and the user did a search for Tom Cruise, then Google will determine that the DMOZ snippet would be a better fit for that search result. The snippets are search dependant.
If you want to be sure that the DMOZ snippet never appears, then you can instruct the search engines, including Google, not to use it:
<meta name="robots" content="noodp, noydir" />
In the example above, "noodp" means not to use the description from DMOZ (Open Directory Project), and "noydir" means not to use the Yahoo Directory description either.