For the last few years, my friend, DPR Jones has been running an annual charity telethon benefiting Medecins sans frontières, also known as Doctors without Borders. It is normally a 24-hour event with guest hosts taking turns running the show from all over the world. It has also been (I think) the largest virtual gathering of atheists in that many of the world’s best known champions of freethought have participated in the show, and it’s generally a good time.
It’s always been in September until now. The full 24-hour show had to be moved to November this year, and I will promote that one more as the time draws near, but there will still be an eight hour show on tonight, (midnight British Summer Time, 6:00pm central).
Check the links on the Magic Sandwich Show website, including the donation and just giving pages.