ZOONIVERSE: Not sure if this squarely fits within the scope of this assignment, but this site is an incredible hub for citizen science projects. They describe themselves as the world's largest and most popular platform for people-powered research. Their goal is not only to engage people without advanced/specialized degrees in big data projects, but also to make data sets that would not be available without engaging an army of amateurs.
They have 19 different projects, but here are some of my favorite. All of them make their data public; and some have need live action feeds.
Anno.Tate. - There's no live feed because how could one possibly share sketchbooks in aggregate, but these are delightful to look through.
CATTfish: I'm possibly interested in doing something water related for this class, so I was happy to find this project. It started as a Carnegie Mellon team and then grew into a company. It tracks water quality across several measures to look for changes over time.
They have a public data component fed by the sensors, but there's obviously not enough of them to create a useful data set or impressive visualization.
PRESSURE NET: This Android app uses barometric sensors built into select phones to create accurate, hyper-local readings that both provides more accurate weather information, but also improves predictive models for weather patterns.
Although it's not flawless, I think it's an interesting nod to the types of hyper specialized data interpretation possible when sensors are ubiquitous.