This is an interesting one. It's a Geiger Counter, which we admittedly don't know much about, but it's designed to detect radiation.
As the image above shows, it's designed to plug directly into an iPhone, which can then be distributed throughout Japan to send out nuclear radiation data via RDTN.org. The information can be read by scientists as well, and they can explain what the data means to the rest of us.
The project comes of course from the concern of radiation levels in Japan right now, and because levels must be constantly monitored in various areas, this allows for that. Here is a non-n00b breakdown, by the people behind the project:
RDTN.org is a website whose purpose is to provide an aggregate feed of nuclear radiation data from governmental, non-governmental and citizen-scientist sources. That data will be made available to everyone, including scientists and nuclear experts who can provide context for lay people. In the weeks following launch, it has become evident that there is a need for additional radiation reporting from the ground in Japan. This Kickstarter project will help us purchase up to 600 Geiger Counter devices that will be deployed to Japan. (The project minimum will fund 100 devices). The data captured from these devices will feed into the RDTN.org website and will also be made available for others to use via Pachube, an open-source platform for monitoring sensor data globally. RDTN.org field members will be trained by RDTN.org advisors to properly use these devices. The field members will be required to report to the website 8-10 times per day.