Bill Gates has dropped by Reddit a couple times in the past, and he's doing it again this afternoon for an AMA starting at 1:15PM ET / 10:15AM PT. Though the spirit of an AMA is that people on Reddit can ask the person anything, Gates is probably interested in talking about his recently published annual letter, which outlines his views for how technology can help improve the lives of the poor. Last week, we spoke with Gates at length about what the next 15 years are going to look like — as you can see in the video above — and he's even guest-editing The Verge in February to help us find out. We've already asked him plenty of questions, so now's the time if you have some of your own.