The one ecard - you will need to send your client, customers, friends, family - your entire network and future prospects to share your perpetual contact info.
One single custom link to all your personal contact info: Name, Tel, Cel, Email and Website. Update you info as it changes - your clients and friends will be able to reach you through your personal or business links.
Changing jobs, company, address or cell phones. Everybody in you network can go to your Digital One Card link and get the latest info.