How to download a webpage's all images at once? For example, I love military decorations, and here's Wikipedia's Service Ribbon, how can I download all the ribbon images at once instead of clicking them one by one and then select "Save image as"?
Automator
Use OS X's Automator.app to find, extract, and save the images from your current web page. The combination of Actions needed are:

Get Current Webpage from Safari
Get Contents of Webpages
Save Images From Web Content

To learn more about using Automator, see Apple's Mac Basics: Automator.

Terminal
An alternative approach is to use curl through the command line, What's the fastest and easiest way to download all the images from a website.