Version:            (using KDE Devel)
Installed from:    Compiled sources

In Outlook or Act when you look at a contact it's possible to see all the linked emails or appointments in a listbox.  Clicking on any of these takes you to the event or email in question.  This is really nice feature that you can currently work around using search folders but would be great to have integrated into the addressbook.  It's a logical idea to display all related entries with the contact :)