Let's say I were to start a niche directory and put all the links from a dmoz category in it before I started promoting. Could this be considered duplicate content?
Yes, but you can do it if you provide the relevant attribute to dmoz on the bottom of each page, look at thier terms.
I guess this would be the one, thanks... 1. If the Open Directory in whole or in part, or any derivative work thereof, is made available via the Internet or internal network/intranet and/or information contained therein is directly accessed or linked via the Internet or internal network/intranet then you must provide the appropriate Netscape attribution statement as described in the page(s) at the URL(s): http://dmoz.org/become_an_editor
To answer your original question, it certainly will be duplicate content. You will have to add something to it (such as website reviews or ratings) to make it original. And even then, you can probably forget about getting that content ranked in search engines, unless you totally rewrite all the descriptions.
There are literally hundreds of DMOZ clones that are not indexed by google or are very much supplemental.
It's hard to find examples when they're all out of the SERPs, but I would agree with this. A few years ago getting a link in DMOZ really meant something, because of all the clones. So you would get a link in, then do a link: search on Google and find your link in hundreds of clone directories. Another way to test this is to do a search for your Dmoz title in quotes, plus the title or description of another website listed in your Dmoz category. A while back that would return oodles of results. Now I'm seeing in the region of between 10 and 40 results, but significantly a lot of these duplicate results are not in English.
Thanks for the heads-up. I wasn't trying to get away with anything, just wanted a little substance to my site before asking people to contribute to it. I had a feeling that would be a bit too easy though.
People are actually still creating DMOZ clones, but not as much as they did about year or 2 years ago. jlennon: i wouldn't put any links in my directory, i would rather write 100 word description for each category and subcategory. A lot of work? I know that, but i belive it will put you light years ahead from your competition.