I do submit any new sites I create to search engines, but I don't do it through the "old" method of just submitting a URL (such as here on Google). Instead I create an XML sitemap and I then go to each search engine's webmaster management console and submit the site. I also include the path to the sitemap in the robots.txt just to make sure for those that don't have consoles or ones I haven't submitted the site to.
URLs for the 3 major search engines webmaster management console:
Text to put in the robots.txt:
Sitemap: http://www.example.com/sitemap.xml
I also often ping the search engines to let them know a new sitemap is available. This site has a little page where you can submit your sitemap to a bunch at once, although it no longer works for Google: http://www.sitemapwriter.com/notify.php
Of course, all this said, if there aren't links to your site then all of this is useless. Getting an account on sites like Twitter, Facebook, YouTube can be helpful in getting links to your site, especially if you post useful links/content.