Politifact: Fact checking for U.S. politics. (Fullfact does the same job in the UK.)
Geofedia: Social media search and monitoring by location.
Google Maps and Street view: Use to compare a video or photo with the location where it was purportedly taken. Flickr also has a function that allows a search for photos on a map.
Wikimapia: Wikipedia for maps, which allows anyone to "tag" a location and describe it. This is often useful for identifying districts or buildings that don’t appear on commercial map services like Google Maps. Maplandia has similar features.
Google Image search: Use "Search by image" rather than text to find where an image appears online. It also returns visually similar images. Often there will be dates attached, giving you an idea of the history of an image.
TinEye: An alternative reverse image search. Sorts results by image size and by how much the image has been modified.
FourMatch: Image forensics to detect whether or not an image has been tampered with. It's a paid service but you can get a demo key for $20 which lets you analyze 30 images in 30 days.
DomainTools: Check domain ownership.
Spokeo People Search: Find information about people in the U.S.
