Douglas Crockford's typeOf and Jaycliff's innerTypeOf

typeof.js

function typeOf(value) {
    "use strict";
    var type = typeof value;
    if (type === 'object') {
        if (value) {
            if (Object.prototype.toString.call(value) === '[object Array]') {
                type = 'array';
            }
        } else {
            type = 'null';
        }
    }
    return type;
}
function innerTypeOf(arg) {
    "use strict";
    return Object.prototype.toString.call(arg).slice(8, -1).toLowerCase();
}
function innerTypeOf_complicated(arg) {
    "use strict";
    return Object.prototype.toString.call(arg).match(innerTypeOf.regex)[1].toLowerCase();
}
innerTypeOf.regex = /\s([a-zA-Z]+)/;