Neat calendar service. Sync with desktop clients, mobiles, etc and then displays public availability and allows people to schedule events while handling timezones smoothly. Hat tip Anthony Feint.
Very detailed FAQ on Gnome Evolution with links to a wiki and some other resources.
A blog post on how to remove duplicate address book entries using sed, uniq and sort. It suggests converting all vcard entries to single lines, using sort then uniq and finally converting back. It removes absolute duplicates.
This is a simple perl script which *very crudely* removes duplicates in Evolution data. It deletes any contacts with the same name.