I've written a little web script that has no security, no protection, and an obscure URL. Then I send that URL to all the people I'm interested in getting toge

I've written a little web script that has no security, no protection, and an obscure URL. Then I send that URL to all the people I'm interested in getting together. They click buttons on it to suggest what dates and times they can and can't make. The system gradually settles on one that works for the majority, and that's it. If you don't want something secure and general, if it can be largely ad hoc and mostly bug-free, it's easy.