Vote for QSync for Outlook
Synchronization tool for Outlook. QSynchronization adds a new page on the folder properties dialog, in order to set up synchronization. For every folder, that is to be synchronized, a target folder and some settings are given. Synchronization may be bi-directional or unidirectional in any direction. Permanent synchronization copies all new entries in either direction as soon as they are created or modified. Synchronization of deleted items removes items from the target folder if they are deleted in the source folder and vice versa. Features include: Synchronize folders on a notebook with a desktop PC; Synchronize your private calendar with a public calendar; Backup your data to another PST file and more.