Web 2.0 is one of the best methods of getting free traffic as well as increase your site's PageRank. Below I will give you a list of Web 2.0 sites. Note that this list is not exclusive and I will update it from time to time. So please bookmark this page:
http://onlywire.com (this is actually a free service for submiting your site to 15 social bookmarking sites)
http://allmyfavorites.net
http://backflip.com
http://blinkbits.com
http://blinklist.com
http://bloghop.com
http://blogmarks.net
http://blogmemes.net
http://bookmark-manager.com
http://bookmarktracker.com
http://buddymarks.com
http://citeulike.org
http://co.mments.com
http://connotea.org
http://de.lirio.us
http://del.icio.us
http://digg.com
http://fantacular.com
http://fark.com
http://feedmarker.com
http://feedmelinks.com
http://furl.net
http://givealink.org
http://gravee.com
http://hyperlinkomatic.com
http://igool.com
http://kinja.com
http://linkagogo.com
http://linkroll.com
http://lister.lilisto.ocm
http://listible.com
http://ma.gnolia.com
http://myspace.com
http://myweb.yahoo.com
http://www.google.com/bookmarks
http://propeller.com (formerly Netscape.com)
http://netvouz.com
http://newsvine.com
http://popurls.com
http://rawsugar.com
http://reddit.com
http://scuttle.org
http://shadows.com
http://simpy.com
http://slashdot.org
http://smarking.com
http://socialbookmarking.org
http://spurl.net
http://squidoo.com
http://stumbleupon.com
http://tablitz.com
http://tag.zurpy.com
http://tagtooga.com
http://tailrank.com
http://technorati.com
http://unalog.com
http://wink.com
http://wists.com
http://www.30daytags.com
http://www.43things.com
http://soc.ialize.us