Add your url minus the www into the DMOZ search and it will tell you if it is listed. That's just in case when an editor reviews the site they would like to include it in the directory but in a different category. But be aware that it can take from a few days to a few years for that review and there is no guarantee the site will be listed at the review. For further deatils see the stickie at the top of this section of the forum.
Aside from looking in or searching DMOZ to discover your listing there are toolbars which indicate whether a site is listed or not. SeoQuake is one such toolbar which adds-on to FireFox; SEO for FireFox is another. Both can be found in the Extensions section of Mozilla.org.