... are a lot more fascinating to me than virtual communities are.

There's so many of which I'm already a part of: My family, my church, friends, my neighbourhood, etc.

I'd really like (closed) websites for all of them, with chat, forum, photos, family trees!

Good PHPBuilder article:

http://www.phpbuilder.com/columns/barnum20030509.php3

Interesting web server for Windows with PHP support - executes SQL queries (on .mdb files) directly by reading them from the URL and returns CSV/XML (for use in applications which can open HTTP HREFs directly, or for distributed web services):

http://badblue.com/helpsql.htm http://badblue.com/prodee.htm

"Friend Of A Friend" = XML vocabulary for person-to-person relations:

http://www-106.ibm.com/developerworks/xml/library/x-foaf.html

Good blogs come as RSS:

http://weblog.infoworld.com/udell/rss.xml

Use a PHP client to fetch and display RSS?

make / ant in PHP:

http://binarycloud.com/phing/

PHP-OO-Web-Application-Framework (using PEAR:DB und Smarty):

http://merlinwork.crealabs.it/index.php

Nice tree view for bookmarks (in PHP):

http://sourceforge.net/projects/sitebar http://www.mindslip.org/sitebar/

Nice interface (down to the details) for a task management application:

http://www.alexking.org/software/tasks/demo/

XML "flat file" database; searchable using XPath (no public version available yet):

http://www.xml.com/pub/a/2003/05/07/bdb.html http://www.merrells.com/john/dbxml/index.html http://www.sleepycat.com/

Cross references in American court decisions, invented by Frank Shepard in the 19th century (article by Bob DuCharme of LexisNexis):

http://www.oreillynet.com/pub/wlg/3153