Suwanose-jima in the Ryukyu islands south of Kyushu is one of the most active volcanoes in the world. There’s a webcam on the island (the last listing in the box to the right), but usually it’s impossible to make out anything beyond a small orange glow just below the center of the image. This morning, however, visibility is was briefly good.
Incidentally, Sakura-jima, jealous of all the attention that Shinmoe-dake/Kirishima has received, has ramped up its activity. There’s a good chance you won’t have to wait long to see a substantial vulcanian eruption on a webcam during daylight hours, and if you’re lucky, you might catch some incandescence at night. ((For a better nightime view, try the fourth listing from the bottom of the right-hand box here.))
Update (2/28/11): After a week of good viewing, the camera image is back to the usual murk. I’d like to send someone there with a bottle of Windex.
Update II: And now the camera is gone.