This is a Cartegraph Labs feature.
Each gadget has the same Actions menu in the upper-right corner of the gadget.
The Actions menu contains the following options:
Click Duplicate to use an existing gadget as the basis for a new gadget. The Title and Chart Color do not duplicate. Enter the chart name and make any needed edits.
Click Export to put the gadget contents into another file format. The options are PDF, PNG, and CSV. The file downloads from the web browser.
Click Remove to remove the gadget from the dashboard. The gadget is still available in the Gadget Library, in case you later want to display the gadget on the dashboard again.