You can share contacts with others even if s/he doesn't use Outlook 2007, although Outlook 2007 users receive the contact as an Electronic Business Card.
Those using an older version of Outlook or e-mail applications that rely on HTML can see the contact information as an image that looks like the Electronic Business Card and a .vcf file attachment. All others, especially those receiving e-mail messages in plain text, receive a contact's information as a .vcf file attachment.
A .vcf file is a vCard file that you can import and export from address book applications like Outlook, Microsoft Entourage, Palm Desktop, and others.
To forward a contact from with an e-mail, click the Business Card icon in the Message tab's Include Group.
Select the default business card or "Other Business Cards" to find a different contact from the "Insert Business Card" window.
The window includes Business Card Preview so you can verify you have the right card since you may have multiple entries for one person.
You can also send a Business Card from the Contacts module. Open a Contact and click Send to see a menu. Select the format to create a new e-mail message where you can enter the recipient and any other information to send in the message.