Yet by the turn of the century, when anyone could take a snapshot with their lightweight Kodak, the seemingly secure position of the photograph among art collectibles was again changing.

ECONOMIST: Snapping up the past

In honor of this quirky American tradition, CNN iReport invited people to take a snapshot of their own shadows for a one-day photo challenge and then share their personal weather predictions.

CNN: Shadows aren't just for groundhogs

In honor of this quirky American tradition, CNN iReport is asking people to take a snapshot of their own shadows for a one-day photo challenge and share their own winter weather predictions.

CNN: Shadows aren't just for groundhogs