Please be aware that Pr changes and this list is correct at time of publishing. This List is not exhaustive but it should get you started. If you know of more please fell free to contact me.
http://classic.elgg.org/_invite/register.php – PR7
http://www.wsis-community.org/account/register.php – PR7
http://community.elgg.org/account/register.php – PR6
http://elgg.net/trac/browser/devel/_invite/register.php?rev=965 – PR5
http://navi.kazusa.or.jp/_invite/register.php – PR5
http://www.hooping.org/forums/account/register.php – PR5
http://www.thevoiceofautism.org/mod/easyjoin/register.php – PR5
http://aty.hipatia.net/elgg/mod/invite/register.php – PR4
http://community.futureeverything.org/account/register.php – PR4
http://www.ipath.org.uk/mod/invite/register.php – PR4
http://rocknrenew.com/elgg/_invite/register.php – PR4
http://sos.tcea.org/elgg/mod/invite/register.php – PR4
http://sppcanada.org/elgg/account/register.php – PR4
http://www.iestarradell.org/elgg/_invite/register.php – PR4
http://demo.agirdurable.net/account/register.php – PR3
http://eduspaces.net/mod/invite/register.php – PR3
http://elgg.ell.aau.dk/mod/invite/register.php – PR3
http://elgg.esu13.org/mod/invite/register.php – PR3
http://elggdev.com/account/register.php – PR3
http://open.evworld.com/account/register.php – PR3
http://pfi.citin.org/beacons/account/register.php – PR3
http://portfolio.evaluation.ulcc.ac.uk/elgg/mod/invite/register.php – PR3
http://teachers4schools.org/_invite/register.php – PR3
http://www.thriiive.com/community/mod/invite/register.php – PR3
http://www.chicagosteelers.com/_invite/register.php – PR3
http://www.savvytaste.com/elgg/mod/invite/register.php – PRhttp://cheweb.org/account/register.php – PR2
http://floridaasians.com/mod/invite/register.php – PR2
http://projectnets.cs.st-andrews.ac.uk/stse/mod/invite/register.php – PR2
http://www.baymazing.com/account/register.php – PR2
http://www.elggspace.com/account/register.php – PR2
http://www.goldengrain.lv/elgg/account/register.php – PR2
http://www.oldeschoolspace.org/_invite/register.php – PR2
http://www.sessochannel.it/mod/invite/register.php – PR2
http://x-smuba.890m.com/mod/invite/register.php – PR2
http://www.dbilbao.com/account/register.php – PR1
http://demo.opsis.ca/_invite/register.php – PR1
http://www.e-randki.com/account/register.php – PR1
http://huegel-hopser.de/account/register.php – PR1
http://primaryschoolteaching.co.uk/account/register.php – PR1
http://profesjonalisci.biz/account/register.php – PR1
http://spicybites.co.cc/account/register.php – PR1
http://stingbat.com/account/register.php – PR1
http://www.aubergeponeyfringant.com/account/register.php – PR1
http://www.justreadit.org/elgg/html/account/register.php – PR1
http://www.nexo.pro/elgg/account/register.php – PR1
http://www.podersecreto.com/elgg/account/register.php – PR1
http://elgg.micds.org/account/register.php – PR0
http://www.elggbrasil.com.br/account/register.php – PR0
http://www.social-network-blog.com/elgg/account/register.php – PR0
