A set of Rock Cycle links collected by @mynictle and shared through Twitter (Thanks Nicola):
http://www.footprints-science.co.uk/flash/rockcycle.swf a drag and drop game to help with the understanding of the rock cycle.
http://users.pipeline.com.au/~jpearce/rock_weather.swf a short animation helping pupils to understand how plant life helps to change the rock formation.
Pearson’s animation of the rock cycle http://www.phschool.com/atschool/phsciexp/active_art/rock_cycle/index.html
Finally Nicola’s own labelling representation in Google Docs, it could be a print out test or IWB screen – use it as it fits your needs best http://docs.google.com/present/view?id=0AZ8kUwRQHEDhZGZrOXM4cmdfNjUxZ3BueHNwd2c&hl=en