An editorial from the Observer posted on the Guardian's website takes a meditative step back, and it's a thought worth repeating:
By colonising the space above our heads and above much of our continent, the eruption provides a reminder of our status in relation to our planet and over which we have arrogantly seized stewardship. We imagine ourselves its master and yet with one modest belch it hems us into our little island, sweeping instantly from the skies the aeroplane, which we consider to be an example of the irrepressible genius of our species... It would be crippling to retain that kind of perspective on a daily basis – anyone who set their watch by geological time would never get out of bed – but a glance at ourselves in proportion to the universe is salutary on occasion... We cannot blame the volcano, only observe how liberating it is sometimes to be powerless before nature.
On a side note, the timing of the massive halting of much of the world's air traffic is interesting (to me) because it comes just a few days after I saw this video (below), which is pretty cool-looking regardless. I wonder how different it would look these days.