PSC (Perl Secure Conf) is a setuid wrapper and Perl module for securely passing configuration data to Perl scripts, especially DBI passwords etc. The wrapper opens a conf file, drops priviledge, and then execs the Perl script, leaving the filehandle available to the Perl script for reading (and writing, if allowed). Config::Secure is a module (available on CPAN as well) that initializes, and optionally parses the config file. Please note this is still vera alpha, yet seems to work smoothly.
Jester/BMD (BookMark Database) is a system for sharing Web bookmarks over the Internet. It works by connecting the personal databases of its users and mirroring changes from user to user so any record added by one user eventually spreads to every other user. This effectively builds a shared collection like dmoz.org, in a database format.