Fernandina volcano in the Galapagos.
Fernandina in the Galapagos has entered a new eruptive phase according to the Geophysical Institute (GI) at the National University of Ecuador (in spanish). Satellite images show a new crater and ash column from the volcano and the GI will look for evidence of new lava flows beyond the "hot points" spotted on the satellite images. UPDATE 4/11/09 9PM: I thought I'd add a link to the story in English now that I found one. There are also some pictures of the lava flows from La Cumbre (There is some confusion about name - Fernandina and La Cumbre are the same thing).
The Galapagos Islands are created by a hot spot underneath the Nazca Plate - similar to how Hawai'i is forming over the Pacific. Fernandina is on the island of the same name and is the most active of the Galapagos volcanoes. Most of the eruptions from Fernandina are lava flows with minor explosive component, including the most recent eruption in 2005. However, in 1968, the volcano had a VEI 4 eruption that produced pyroclastic flows and debris avalanches. The eruption also included a caldera collapse (PDF link). One of the biggest concerns whenever volcanoes in the Galapagos erupt is the effect on the wildlife of the islands so the GI will monitor this new eruption to make sure that the appropriate response can be made to protect the rare flora and fauna - such as evacuating turtles!