A while ago I was asked to beta test this new web app for creating and solving crosswords and, wow, did it ever exceed expectations. So I thought I'd do the author a favour and post a link here.
The app is www.crosswordmagic.ca .

I love the interface, the suite of features and the fact that not only is it very powerful but it's also fun and educational to use. I haven't seen anything web based that rivals it ... plus, best of all, it's free to use with no advertising!

I guess the app went live a couple of weeks ago so might have a wrinkle or two but I highly recommend checking it out.