bobbym has the right idea. There are a lot of free directories to submit through. If you do, try the following guideline: 1) Only submit your website to those who have a page rank of 5 or higher. 2) Only submit to those who will link back to you ( back-links ) 3) Forget the rest. 4) Yes, it will take some effort on your part to get the back-links, but it's worth it.
I do the same. I submit to lots of directories these days. I don't know that if it's helping me but they do help in a small way.
Just make sure it doesn't cause more harm than good. Most of the time, submitting all at once will only make things worse. Do them slowly.
Different people different opinion. In my opinion, if you have cheap labor or if you yourself can, then submit to as many as possible. With some of the startup directories, you don't really know, a few of them may become very big down the road and in process your links will have lotta value.