There are several things that I really like about the Lytro camera. The ability to have photographs that the user can shift the focus on adds a great interactive element to educational uses. In the photo above, you can click on the egg, larva, pupa, and adult of the mealworm, letting students focus on one stage at a time.
There are ways to bring the entire photograph into sharp focus, giving you incredible depth of field for closeup photography. Lytro is also working on software that will turn any Lytro photograph into a 3D image. The camera is small, easy to use, and takes nice photos.
OK, so why did I send mine back? The main problem that I ran into was their proprietary format. The only way to put a Lytro photo on your website, Facebook, etc., is to load the photograph onto Lytro's site, and then link to that photo. This means that your ability to share photos is totally dependent on Lytro's site. If their site goes down, or if they ever go out of business, all of the photos you have already taken suddenly vanish from the internet. I asked Lytro if they are developing software that would let me host the photos on my own server, but they are not currently working on that. I can't afford to spend huge amounts of time developing resources that could vanish at any moment.
Smaller problems included the low resolution of the photographs, compatibility problems on some computers, and the lack of any way to adjust contrast, saturation, etc. on the photos. I could get past these, if Lytro ever develops software that lets me use the photos without being dependent on their site. I will continue to watch this camera, and hopefully will be repurchasing one in the future.