Thanks for starting this thread. Though I'm not a big user of real jigsaw puzzles, I really like the computer ones. I've googled them before but didn't really locate anything good before I gave up looking.
I posted this jigsaw game on the Infinite game page yesterday but it wasn't put up until about 4-5 hours after I submitted it (about after 2:30 am EST). It’s a jigsaw puzzle called Bigjig. Go to http://www.lenagames.com/bigjig.htm It isn't actually free, it's shareware--but it’s free to download and use (No game functions are disabled). If you visit the website, you can get one free puzzle every week to play within Bigjig. If you purchase and register it, you get over 300 jigsaw puzzles and a program that allows you to make jigsaws out of your own pictures to use within Bigjig.
There is a free jigsaw puzzlemaker on her website also. I haven’t used it yet as I never really noticed it before yesterday so I cannot attest to its usefulness. Here is the link. http://www.lenagames.com/astra-gift.htm
Here is a description although it doesn’t say that it works with Vista.
“Astra Gift Maker is a free tool for creating stand-alone jigsaw puzzles out of arbitrary images (family pictures, images downloaded from the Internet, etc.). Create a jigsaw puzzle and email it to your friends or publish it on your web page.
No additional software is required to put such a puzzle together: everything is included in the puzzle itself. Yet the puzzles come out compact and suitable for distribution.”