Here's one that I actually wrote for home use cataloging several thousand pictures:
Write a program to scan a user-supplied directory for .jpg files. Then, output the list of files, sorted by date picture was taken, as an HTML file with hyperlinks to each pic.
Bonus points: make the scan recursive so that all subdirectories are scanned also.
Double Bonus points: make it possible to run your program a second time, supply a different directory, and add to your list of pictures. A couple of things about this one are non-trivial!
You will need a module to help you read the .jpeg metadata. See here: