I think Giving Tuesday is a relatively new designation. But in the clutter of random "International Day of..." declarations, giving seems more worthy than most. Have you given yet? I gave. I can't tell you what or where or to whom (I think that takes some of the juju out of it), but I highly recommend.
Since I live and work in a world that celebrates the greatest in home design, I find it important and very troubling to remember that some people don't even have a safe, warm place to sleep at night. If you live in the Toronto area, here is a helpful list of places and people that need what you can give. Just click the image, then give: