The Open Directory Project
www.dmoz.org
Dmoz is the largest human edited directory on the internet. Every catagory on Dmoz has or is looking for a volunteer to choose which sites are added. This makes it one of the few really useful directories on the internet because rather than being full of completely random sites, they are all vetted so all the junk should be filtered out by the editors. However, this does make Dmoz very hard to get onto.
They are very strict about the process of submission at Dmoz; you pick the catagory you want your site listed under (And you MUST choose the most accurate catagory or you will be penalised for this), then you add all the standard details about your site (URL, Description etc), you click on "Submit" and then you wait. And you keep waiting... And when you've waited long enough you wait some more!
There are mixed views on how long you should wait after submiting your site to The Open Directory Project, but the basics of it are that once your site is submited there could be several months wait for it to be reviewed and whatever the outcome they dont neccesarily let you know, and if you re-submit before your site has been reviewed it will either be pushed to the bottom of the list or it will be banned. So submiting to the ODP is a very delicate process! In the past 3 years I have submited 4 sites and none of them have been successful:( But Il keep trying.
Of course they are always looking for volunteers at the ODP but you really have to show that you know your stuff in the particular catagory you choose, you have to have a number of sites already in mind to submit and again you have to wait to here whether or not you are excepted. Everything concerning the ODP is quite difficult, and this may seem like a cynical review but in all fairness, that is why the ODP is so good, because they take great pain to make sure if I site goes on, it SHOULD be there.
The Open Directory project are definately noticed for their efforts - alot of the major internet search engines, Google included use results from the ODP and mix them in with their own. So if you are trying to move up the ranks on Google, getting listing on the ODP is a very important step. But remember, take your time when submiting your site!