new hosts appearing between 2011-08-20_1500 and 2011-08-20_2000:
www.chatvibes.com
www.perl.org
www.rcn.com

hosts disappearing between 2011-08-20_1500 and 2011-08-20_2000:
sify.com
toolserver.org
www.iij4u.or.jp
www.uni-muenchen.de