It definitely helps a bit to be listed in DMOZ -- though theres no guarantee that it will increase your rankings. However, DMOZ is a pretty authoritative directory and it does help if you get accepted.

Assuming you actually get listed in DMOZ, and that is a big if, you may see an improvement in rankings but most likely not. Although a link from DMOZ is more valuable then a link from a regular directory their links aren't as powerful as many people like to make them out to be. Unless the search terms you hope to rank well for are very niche specific I wouldn't expect that link to make any kind of difference. But it is good to have.

I think the biggest benefit to being in DMOZ is not from the site itself but from being listed on partner sites (ie Google Directory) and the dozens of individual directories which scrape DMOZ content. Overall it gives you links on targeted pages from a wide array of different domains.

That used to be helpful until Google implemented their duplicate content filters. Overnight those DMOZ clones became worthless. Heck, even Google removed the directory from their home page. But that probably is more of a reflection of how DMOZ operates no then anything else.

I still think it could be useful if done right. Sites that use DMOZ content don't necessarily have to look or act like DMOZ. Heck, with a copy of the DMOZ database at my disposal, I could put some "Related Links" towards the bottom of every forum thread, for example. It would more be utilizing the DMOZ database than being a clone or copy-cat.

Unfortunately you are more creative then most other webmasters. Most sites just use the data for cloning Dmoz. No matter how you look at it, though, being in Dmoz is definitely a positive. (Good luck getting in though....)

> Unfortunately you are more creative then most other webmasters.
No arguments there

Why, I wonder, DMOZ wouldn't accept a site? Do you guys know some reasons why they wouldn't?
I haven't submitted my website to them yet, but I'd like to know somethings they don't like in a website that makes them decide not to to accept certain site so I can make some changes to my mine before I submit it to them.

Some categories don't have editors. Others don't have active editors. Some have corrupt editors who keep competitors out by rejecting or ignoring their sites. Basically it is a crap shoot. Just submit it and forget it.