The Noun Project.

I came across this very cool website yesterday while searching for images of baby sloths: The Noun Project, a free site dedicated to sharing symbols and enriching our language through symbols and images.
From their mission statement:

The Noun Project collects, organizes and adds to the highly recognizable symbols that form the world’s visual language, so we may share them in a fun and meaningful way…We think a language that can be understood by all cultures and people is a pretty amazing thing. We also think our symbols and the objects or ideas they represent are works of art worth celebrating.

The symbols range from sort of silly (and potentially useless, like the sign for drawbridge) to really damn cool (boycott! urban farm!). And you can download whatever symbol you might need for freeā€”or submit a symbol, if you’re artistically inclined.

See for yourself.