Contact Delegation is now available in Gmail. You will be able to allow a delegate to see your contacts as well as your email.

Gmail Delegation provides users the ability to delegate access to their Gmail account to someone else in their organization so they can read, send and delete messages. With this added feature, a delegate will have the ability to access the other person’s contacts by clicking the Contacts link.You cannot give anyone permission to change your account password or settings, or chat on your behalf. Also, you can specify up to 10 users.

Available in Premier Edition and in all languages supports by Gmail.

Please see below for more detail:

http://googleappsupdates.blogspot.com/2010/03/contact-delegation-available-in-gmail.html