First there was reciprical link building. Then Google caught on and began discounting reciprical links. After that blogs and wikis began to appear and rampant SPAM forced wide spread usage of the NoFollow tag.

After Reciprical linking came Directories. Now some say Directories are being discounted by Google as well and that you get little for the time and effort you put into doing hundreds of submissions.

I've submitted a couple of sites to directories. This doesn't make me an expert but my experience has been basically positive. (In case you are interested I use Directory Submitter.)

I run a highly technical engineering site in a small niche. As a result I was being largely ignored by Google in favor of Wikipedia (here's their article on web directories). Then I submitted my site to about 350 directories over the course of a few days (10 minutes here, 10 minutes there until it was done).

After submitting my site to the directories my page rank didn't change but my site was getting crawled much more frequently. This meant my new pages were included in Google's search results in a couple of days.

Within a few weeks many of my pages were showing up in the top ten of the "long tail keywords". My site's topic area is Control Systems and the top ten search results for that keyword are dominated by Wikipedia, IEEE, and universities. It is unlikely that I will ever knock them off their top spots for that keyword. However, there are specific design and analysis topics (those "long tail keywords") where those sites have little or no presence allowing me to rank high. It wasn't until a few weeks after I completed my Directory Submissions until I achieved those high ranking spots. Often with articles that had been on my site for months. (In my other Hub on Directory Submission I go through the benefits of Directory Submission in more detail.)

Alternatively I began a Usenet portal this last fall and almost immediately began submitting it to directories. This has not produced any results but that site is a portal to a Usenet group and probably suffers from some duplicate content penalties.

 Obviously, if you run an established site with a page rank above 4 then you don't need to bother with directory submission.  I'd guess you've already done it but don't need it now.  However, if your site is new or lacking inbound, one-way, links then directories still help.  Submission to the web directories is free, software is available to significantly decrease the required time, and the links are (mostly) permenant.

I wouldn't recommend writing new anchor text for every directory.  In fact I would recommend doing the bare minimum for directory submission and worry about more important things.