Submitting to Directories are an excellent way to get backlinks for your site as well as little traffic. The more directories you submit to the more backlinks you will get. The more backlinks you get can mean a better PageRank for your site. There are thousands to hundreds of thousands of directories out there. Some are free, some are paid, and some offer free or paid with reciprocal link, meaning you give them a link back on your site. All three types are worth it. Paid if you believe the link will be worth it and will get a lot of PR.
One example of a great web directory to submit to is LinkSlinky Directory. It has all three options. Several paid ones, a free one, and a reciprocal free link. Submit your page today and get another backlink and expect it to help you with your pagerank.
I will list more directories that are free and paid. So just go and look for directories to submit to today, it can only help you.