I used Titanium Appcelerator to build it, and was really impressed with how much easier it was to develop using Javascript as opposed to Objective-C. This is probably due to having quite a bit more experience with Javascript than the later, but I really enjoyed it and would recommend it to anyone wanting to dive into iPhone App development, but not ready to take on learning Objective-C.

keycode = {

	getKeyCode : function(e) {
		var keycode = null;
		if(window.event) {
			keycode = window.event.keyCode;
		}else if(e) {
			keycode = e.which;
		}
		return keycode;
	},

	getKeyCodeValue : function(keyCode, shiftKey) {
		shiftKey = shiftKey || false;
		var value = null;
		if(shiftKey === true) {
			value = this.modifiedByShift[keyCode];
		}else {
			value = this.keyCodeMap[keyCode];
		}
		return value;
	},

	getValueByEvent : function(e) {
		return this.getKeyCodeValue(this.getKeyCode(e), e.shiftKey);
	},

	keyCodeMap : {
		8:"backspace", 9:"tab", 13:"return", 16:"shift", 17:"ctrl", 18:"alt", 19:"pausebreak", 20:"capslock", 27:"escape", 32:" ", 33:"pageup",
		34:"pagedown", 35:"end", 36:"home", 37:"left", 38:"up", 39:"right", 40:"down", 43:"+", 44:"printscreen", 45:"insert", 46:"delete",
		48:"0", 49:"1", 50:"2", 51:"3", 52:"4", 53:"5", 54:"6", 55:"7", 56:"8", 57:"9", 59:";",
		61:"=", 65:"a", 66:"b", 67:"c", 68:"d", 69:"e", 70:"f", 71:"g", 72:"h", 73:"i", 74:"j", 75:"k", 76:"l",
		77:"m", 78:"n", 79:"o", 80:"p", 81:"q", 82:"r", 83:"s", 84:"t", 85:"u", 86:"v", 87:"w", 88:"x", 89:"y", 90:"z",
		96:"0", 97:"1", 98:"2", 99:"3", 100:"4", 101:"5", 102:"6", 103:"7", 104:"8", 105:"9",
		106: "*", 107:"+", 109:"-", 110:".", 111: "/",
		112:"f1", 113:"f2", 114:"f3", 115:"f4", 116:"f5", 117:"f6", 118:"f7", 119:"f8", 120:"f9", 121:"f10", 122:"f11", 123:"f12",
		144:"numlock", 145:"scrolllock", 186:";", 187:"=", 188:",", 189:"-", 190:".", 191:"/", 192:"`", 219:"[", 220:"\\", 221:"]", 222:"'"
	},

	modifiedByShift : {
		192:"~", 48:")", 49:"!", 50:"@", 51:"#", 52:"$", 53:"%", 54:"^", 55:"&", 56:"*", 57:"(", 109:"_", 61:"+",
		219:"{", 221:"}", 220:"|", 59:":", 222:"\"", 188:"<", 189:">", 191:"?",
		96:"insert", 97:"end", 98:"down", 99:"pagedown", 100:"left", 102:"right", 103:"home", 104:"up", 105:"pageup"
	}

};

Typically, you would have an event listener on an input that would call keycode.getValueByEvent(). You would have to pass in the event, (which is by default the first parameter passed into your event listener function). This code handles the shift key modifier and the value that results from using it.