I recently added a few sites to a lot of directories and I have seen the SERPs improve. Adding to directories is always part of my new site promotion. I agree that it is not what it used to be but my stance on
SEO is that a little of a lot is always good, as long as you do not overdo any aspect of your
SEO promotion to appear spammy.
I always time delay any submissions and I have recently found Submit2Please a great service for good money.