I was amazed by QR codes recently. Its easy way of sharing information visually. This information can be grabbed using barcode scanner(through camera); so just by pointing camera, you grab it.
I am happy that QR codes are used in android very nicely. All application's URL are encoded using QR. it saves effort to remember, type and locate application. All you need is barcode scanner application. QR code generators are available online as well http://zxing.appspot.com/generator/
I see many more usage of this technology in future.