Google Contacts
Google Contacts enables you to run your own Contacts service within your Google Apps domain. This is a cloud-based Contacts service that enables you to access your contacts from virutally any device. You can access your Google contacts from a smart phone, such as an iPhone or a Droid, and you can use Web browsers to log on to your contacts from virtually any desktop, laptop, or mobile devices, such as the iPad or the Zoom. In addition to entering addresses and adding contacts, you can create groups and mailing lists.
To find out how easy Google Apps makes it to set up your own contacts service, follow this link to the Google Contacts tutorial.
If you have not yet learned how to get your Google Apps domain, follow this link to the Google Apps Overview.