Check this out: http://www.daniweb.com/techtalkforums/thread59099.html. There's a list of sites on where you can submit your Press Release.
Create an article about the niche of your site and submit them on article directories. There's a resource box on where you can put something about you(the author) and you can put links to your sites in there. Check this out: http://forums.digitalpoint.com/showthread.php?t=66576. It is 300 Article submission sites.