Just to make the examples look a bit less amateurish, perhaps better to replace the various alert(...) statements in examples 1 and 2 with a comment and elipsis?

In example 1:

if(window.navigator.maxTouchPoints>1)
    alert("Your user agent and hardware support multi-touch!");
}

change to

if(window.navigator.maxTouchPoints>1)
    /* User agent and hardware support multi-touch */
}


In example 2:

switch(event.pointerType) {
    case "mouse":
        /* mouse input detected */
        ...
        break;
    case "pen":
        /* pen/stylus input detected */
        ...
        break;
    case "touch":
        /* touch input detected */
        ...
        break;	
    default:
        /* pointerType is empty (could not be detected)
           or UA-specific custom type */
        ...
}