Syncman synchronizes your Mac's built-in Address Book with your Gmail Contacts with a minimum of fuss, hassle and frustration. Syncman does one thing and does it well.

Features:

• Three different synchronization strategies: Bi-directional sync between Address Book and Gmail, One-way synchronization from Address Book to Gmail, One-way synchronization from Gmail to Address Book.
• Support for most standard contact fields: Name, Company, Title, Notes, Email Addresses, Phone Numbers, IM Accounts (AIM, Jabber, MSN, ICQ & Yahoo)
• Scheduled synchronization with configurable 'bother level'.
• Can optionally run in the menubar as a background application (especially handy when using scheduled synchronization)
• Works with both Gmail and Google Apps.
• Shows you all proposed changes before it makes them.
• Optionally synchronize Gmail's "Suggested Contacts".