It's been quite a day for big earthquake news, with two large earthquakes (magnitude 5.3 & 5.1) near the Bárðarbunga volcano in Iceland and an earthquake of 6.1 magnitude near American Canyon in California.
Perhaps unsurprisingly the USGS provides one of the best near real-time maps of earthquake activity. The Latest Earthquakes Map provides you with a number of options to view earthquake activity over the last 24 hours, the last week or the last month.
The map also allows you to overlay plate boundaries and US fault lines on the map.
The Ö-Files - Live Earthquake Map uses Google Maps and the Simile Timeline with a number of data sources to also provide a live map of earthquake activity around the world.
The map is updated every five minutes to show the latest reported earthquake and you can use the time-line to explore earthquakes over the last seven days. It is also possible to refine the results shown on the map based on the different data sources.
Another source for the latest earthquake activity is Stanford University's Quake-Catcher Network. The Quake-Catcher Network links participating laptops into a single coordinated network to detect and analyze earthquake activity.
Many laptops these days are built with accelerometers that are designed to protect your hard drive from damage. The accelerometer detects sudden movement and can switch the hard drive off so that the heads don't crash on the platters. The Quake-Catcher Network realized that they could create the world’s largest and densest earthquake monitoring system simply by using the data from accelerometers in the world's laptop computers.
QCN uses Google Maps to show the data collected from participating laptops and from participating desktop computers with USB sensors. The map also shows the latest USGS reported earthquakes.