The Solar Dynamics Observatory has released a new video of a very active Sun. The first video starts at 11:35 UT on March 24, 2011. Several flares are visible. The second video is from March 19, and shows a "solar prominence" eruption. According to NASA: prominences are large, bright features extending outward from the Sun’s surface, usually from 2 sunspots. Prominences often from in a loop shape, as can be seen in this video. What you are seeing is plasma trapped in the magnetic fields. Prominences are easier to see when they are on the limb of the Sun, like this one. Filaments are simply prominences see from directly above.

Some of the SDO team will be in San Diego on August 21-25th for the SPIE International Symposium on SPIE Optical Engineering & Applications, held at the San Diego Convention Center.