This is another debatable question. The argument for submitting to FFA Sites and _link_ Directories is _link_ popularity. However, most, if not all, search engines do not count _link_s on all these sites.

FFA (Free For All) sites are primarily used by spammers and the search engines know this. At one time they may have been worth submitting to, but those days are long gone. Due to the amount of spammers submitting useless information, the search engines decided to disregard these sites.

_link_ Directories are slightly different. You can create _link_ popularity by submitting to high ranked _link_ directories, but there are few that are of any quality. DMOZ, Open Directory Project, is the exception. I recommend submitting to this site as most major search engines use their data_base_. Keep in mind that you would only want to submit to DMOZ once, then forget submitting to them again. You probably wont get much out of most of the other directories.

The bottomline, do a little research on the sites you are thinking of submitting to. Some may do more damage than good. A little research can save you a lot of headaches later.