This is one of Magnus' toys. Get the source of this script (SVN: browse/use).
For more information, see Catfood (Category news feeder) on meta. Bug reports and feature requests

This is a category-based RSS feed for Wikimedia Commons.
The images are ordered based on the time of the addition of the image to the category, latest additions first.
Alternatively, you can see the last images uploaded by a user.
You need to supply at least a category or a user name to get a feed. Enter the information below, or use URL parameters (click on "Do it!" for a demo).

Language
Project
Category	(without "Category:" prefix), or
Depth	(0=just this category)
Namespace	(6=images; 0=article)
User	(Wikimedia Commons user name)
Size	200px 250px 300px (maximum height/width)
Number	(last X images/pages; 1-100)

Or get a feed of the Media file of the Day!