The people behind HEWS (Humanitarian Early Warning Service) describe it as "a global multi-hazard watch service to support humanitarian preparedness".
They collect hazard early warning information from across the globe to allow for efficient planning and decision-making. As a result, there are loads of interesting maps (and did you know there'd been a 5.5 earthquake in Chile this morning?), and links to a range of sites, for example the USGS.
Well worth checking out, especially for Yr9 who are "doing" Natural Hazards at the moment...
Thanks to Ollie Bray for highlighting the site on his blog, and to Rob Chambers for pointing it out to me as well.