Zooniverse connects you to dozens of research projects in need of community scientists. Projects cover a wide array of topics, and all you need to participate is a computer (some projects support mobile devices) and internet connection.
You can watch footage of the sea floor and record animal sightings to help with a Swedish study on marine biodiversity; transcribe handwritten correspondence between anti-slavery activists in the 19th century; watch trail camera footage from the African savanna to identify passing animals; or examine fossilized leaves for clues about past climates, just to name a few of the nearly 100 programs you can select.
Find out more and get started at the Zooniverse website.