Everybody loves one-way links (also called non-reciprocal links). Search engines give them more weight, and they mean you don't need to send traffic back to the source, but can keep it on your site or network. So here's a little encouragement on submitting to directories and other places you can get one-way links from.
First, I'm adding this to Technorati. I had a link here to Technorati, but have since removed it. The link was necessary to have Technorati list City SEO. Once they verify it, I can delete the link and have a one-way from Technorati. Next, I evaluate what type of site I'm running. There are blog indexes, forum indexes, and even directories of directories! Doing a quick Google search for 'your type of site" + "directory" will usually return some good things. Technorati is a "blog directory." Further to that, I search for directories on my topic. I do the same thing as in the previous point, but change the type of website I'm running to the type of content (i.e. keywords) I have. Finally, and this is actually a trick I picked up from Ralph Wilson, who himself got it from Bill Hartzer, search for "your topic" + "add URL." Then search for "your topic" + "submit site," and other variations. This will help you find the little places off the beaten path.