Does someone know any good websites where I can add my website so that my Google PR will improve without placing a link back from that website?

You can start with dmoz.org and then go to this page for a list of other general directories to submit your website to: http://www.webworkshop.net/seoforum/viewtopic.php?t=944

A list of some of the Human edited Directories..

http://www.aardvarkbusiness.net/add_url.shtml
http://www.allbusiness.com/contact_...s_directory.asp
http://www.baminfo.com/suggestion.asp
http://www.bizlink.org/suggest.asp
http://www.bocat.com/b2b/submitsite1.htm
http://www.business-opportunity.biz/dir/add_link.html
http://www.canadaone.com/business/addurl.html
http://www.ceotrak.com/theIndex/signup-standard.asp
http://www.clickit.com/touch/add-link.htm
http://www.evresi.gr/url.htm
http://www.eztowork.com/add_link.html
http://www.forexdirectory.net/submitforex.html
http://www.freeadvertz.com/businesslinks/add_link.html
http://www.home-business-tips-newsl...s/add_link.html
http://www.internetb2blist.com/adds/adsB125x125.asp
http://www.mbnet.com/links_add_form.asp
http://www.moneywebsearch.com/cgi-b...l.cgi?Category=
http://www.morgle.com/newinput
http://www.presentationbiz.co.uk/links/add_link.htm
http://smallbiz.searchking.com/getlisted.html
http://www.superpages.com/about/new_chg_listing.html
http://www.thomasregister.com/
http://www.wand.com/english/queries/w_reg.asp
http://www.whoswhoontheweb.com/cgi-...ory/newuser.cgi
http://www.work-at-home-business.com/addlink.html
http://www.workathomecentral.com/wo...e/add_link.html
http://www.macsysga.com/hitcounter.asp
http://www.aatrax.com/addurl.htm
http://www.abc.net
http://accessweb.ws/
http://search.asiaco.com/cgi-bin/addurl.cgi
http://www.bbc.co.uk/webguide/suggest/
http://www.chiff.com/suglink.htm
http://www.click4choice.com/cgi-bin/links/add.cgi
http://www.cyberfetch.com/signup.cgi
http://www.gimpsy.com/gimpsy/searcher/suggest.php
http://www.gloose.com/links/add_url_instructions.html
http://www.goguides.org/info/addurl.htm
http://hoppa.com/admin/link/compose/
http://www.imarvel.com/goodidea.htm
http://www.joeant.com/suggest.html
http://www.kingdomsearch.co.uk/submiturl.htm
http://www.landoflinks.com/docs/help/addtop.html
http://www.linkopedia.com/submission/index.html
http://listings.looksmart.com/?sid=lsl100866
http://www.mavicanet.com/
http://www.netinsert.com/en/insert.html
http://onebigdirectory.com/
http://www.openhere.com/
http://www.primesiteuk.com/cgi-bin/search/addurl.cgi
http://www.qango.com/dir/addurl.html
http://searcheurope.com/submit/
http://www.searchpole.com/cgi-bin/l...aform&category=
http://www.searchsystems.net/submit.php
http://www.seeksites.net/linksaddedit.asp
http://www.sgtsearch.co.uk/cats.php
http://www.siccode.com/register.php3
http://www.sightquest.com/how-to-submit.htm
http://www.splut.com/cgibin/suggest...=site&level=000
http://vlib.org/feedback/site-suggest.html
http://www.webbieworld.com/ww/webnom.asp
http://www.webworldindex.com/cgi-bin/pseek/addurl.cgi
http://www.whoisman.net/submithow.htm
http://www.wholeworld.com/info/howtoadd/
http://1st-spot.net/form_urls.html

--James