tel: URI scheme

As a mobile web user, when I find a phone number on a web site, I want to dial the number simply by tapping it. To embed a tappable (or clickable) phone number on a web page, use the tel URI scheme. Here's an example:

Richard's House of Pizza <a href="tel:555-555-5555">555-555-5555</a>

Your web browser renders it like this:

Richard's House of Pizza 555-555-5555