Rhubarb, you don't submit to Yahoo or msn neither. They will crawl your site automatically.
I have at least 10 sites and all of them never submit to major search engines.
However if you are targeting local, you may submit to local search engines, that still counted as a backlink.
What you can also do, bookmark your site to some do follow social bookmarking sites, find it at socialposter.com.
then do some forums links building this work great.
I personally don't use that directory submitter. I use a different one. So I can't tell if it is good for you or not.