Have you received an indication that your site will be added to the directory? If so, you should allow 24 hrs or so for it to show up on the public side of the directory. It will not show up for now using the site search (Search database last updated on: Mon Dec 9 21:32:07 PST 2002) so you'll have to find it by looking through the directory as it could have been listed in a different (more appropriate) category than the one you submitted to.
>> Once your site has been approved in DMOZ, how long before it "shows" in the results? <<
It shows in the public side of the directory usually within minutes, but can take hours sometimes.
The ODP is a directory, so don't worry at all about the Search function at dmoz.org as that is actually just supposed to lead people to the correct category. The ODP is not a search engine (for sites), and the ODP search should not be treated as such. Use it to find useful categories, then browse those categories.