Aficionados of galactic pile-ups can avail themselves today of a set of 59 Hubble images of colliding galaxies, released to commemorate the 18th anniversary of the space telescope's launch.
More: http://www.theregister.co.uk/2008/04/24/colliding_galaxies/
Images: http://hubblesite.org/newscenter/archive/releases/2008/16/image/a/
Those are fantastic images!