Whoever said that curiosity killed the cat must have led a boring life.
Curiosity, which is also the name of NASA's Mars rover, is a good thing. It's what propels scientists and innovators to come up with things like wearable electronics, smart dog collars -- and because they can -- cat headphones.
Last week, we asked Mashable readers to submit photos that express curiosity. The theme opened a wide set of possibilities: things that normally go unnoticed, things hidden from plain view, everyday objects shot from a different perspective. Others took it more literally, sending fun snapshots of pets and children looking at the camera curiously.