Usability 
Mobile Share is a simple but potentially handy new service. It lets you create a personal online contact page, a simple mobile formatted web page containing your name and phone number. A link on the page lets you share it by sending the URL in a text message. Another link lets the recipient add your name and number to their phone's contacts with a single click.
The SMS sending and add to address book functions are implemented using a couple of less common URI schemes; sms: and wtai:// which are supported by most phones. A notable exception is the iPhone, which does not support wtai.