I don't want to post them out of respect for the copyright owner, but check out these amazing photos of the recent (June 4) Puyehue volcano eruption in Chile.
Even more spectacular than the ones of Eyjafjallajökull in Iceland last year. The ash cloud from the one in Chile spread south so far and so thick that flights from Australia to New Zealand were grounded, stranding the renowned Peter Cresswell of Not PC fame. (Serves him right for going all that way for a mere sporting event. :)