A professor from my university bought a Lytro light field camera. We played around with it for a while. Although the Lytro’s form factor is different, you take pictures with it just like you would with your average digital camera. Simply push down the release button and you take a picture. The camera stores the pictures on its internal memory and you have to hook up the Lytro to your computer to download the pictures using the Lytro software. As the camera uses a proprietary format to store the pictures, you have to use the Lytro software to watch them.
As the software is not free, you cannot simply share the pictures (which I strongly dislike). If you want to share them, you can however upload them to the Lytro page and embed them on your website. My professor did this with a Lytro picture of me and I want to share that picture with you. Simply click somewhere on the picture and see the miracle happen (aka the focus change).