I stopped submitting sites to the Big Three several years ago, realizing that an inbound link from a site that is spidered frequently is sufficient to get it listed within a few weeks.
I've noticed that many SEO or online marketing books are still suggesting that people submit their new site's URL through any number of search engine submission websites. In checking client site statistics, I'm seeing (at best) that only 2-3% of search engine referred visitors are coming from somewhere other than Google, Yahoo and MSN.
Does anyone here still use those submission sites?
The only thing these services ever generated was spam email. You provide your title, url, description and email address. Next thing you know you have been opted into hundreds of email newsletters provided by search engines and directories.
I suggest manual submission to some good web directories and forget about the rest.
If you do decide to use a submission service, use a throw away email address.