http://vulcan.wr.usgs.gov/Imgs/Video/MSH/MSH06/MSH06_MOVIE_spine_from_brutus_closein_10-09_to_10-14-06.avi
(Warning - those with dial-up connections might want to be careful)
Wheesh. I always thought volcanoes were weird things, and the idea of rock flowing like water gives me the heebie jeebies - but this, this is honest-to-god visual stuff from a distance to which I'd have to be trussed up like a turkey and taken to kicking and screaming to be at such close range to a live volcano. It's terrifyingly fascinating, though.
I actually wrote a partial for a novel in which a volcano plays a major part. I might have to dust that off and have a look at it again. Nothing like writing about something that scares you to produce emotional oomph in fiction...