Submit your sites to directories with high rankings and get valuable backlinks to your sites. Before submitting follow a couple of tips:.

1. Submit to two or three each day – don’t mass submit, Google will smell a spam rat
2. Make each submission unique when it comes to descriptions
3. Select the most appropriate category
4. Be selective – you do not have to submit your home page

Directories that offer free submissions often require a link back, however, because they are free the backklink can be quite valuable.
http://www.dmoz.org/ 8
http://www.la-ma.org/ 6
http://www.mxdu.com/ 6
http://www.jayde.com/ 6
http://www.mygreencorner.com/ 6
http://www.ghinmeca.com/ 5
http://directory.classifieds1000.com/ 5
http://www.concensus.org/ 5
http://www.directorydice.com/ 5
http://www.domaining.in/ 5
http://www.freewebsitedirectory.com/ 5
http://www.illumirate.com/ 5
http://www.info-listings.com/ 5
http://www.publimix.net/ 5
http://searchsight.com/Directory.htm 5
http://www.uc33.com/ 5
http://www.amray.com/ 4
http://www.a1webdirectory.org/ 4
http://www.boshuda.com 4
http://www.businesspagesupdate.co.uk/ 4

That list should keep you busy for a day or two.