When I was looking for a bit of relaxation, I tried to find an open source, cross platform Jigsaw Puzzle application. That led me to sphaero, which largely did what I was looking for.
I couldn't resist hacking on it a bit. I've kept the heart largely unchanged - the general cutting of pieces, the main puzzle class, and the basic image handling and display. It's been refactored a bit, modernized (so it needs Java 5 or later), cleaned up, and the user interface has been tarted up significantly. To be honest, the basic core was pretty darned good already, the interface just deserved a little extra TLC.
You can also just grab the jar file;
depending on your browser and operating system it may run straight
off. If not then just feed it to java -jar, or just run
the sphaero2 script from the main download (which includes
all the source).
For easy access, I've made some sample images, or download individually:
(I tried emailing Paul Brinkley, the original author, but that bounced. So I can't thank him personally, but Thank You Paul! And if you want to get in touch, my address is on the site here.)
Source on GitHub | Solaris SVR4 Package, Solaris SVR4 sample image Package