Hi Dennis!

3-D pictures of the Sun are taken by two identical satellites called STEREO. STEREO satellites orbit the Sun, about the same distance as the Earth. One of the satellites is travelling ahead of the Earth and the other one behind the Earth. The STEREO satellites are gradually separating from each other. Now they are now about 80 degrees from each other.

The STEREO satellites observe the Sun simultaneously from two different view points. Just like a pair of human eyes, photographs from each satellite will make a stereo pair. The ideal phase for getting 3D images of the Sun was when the satellites were separated less than few tens of degrees (in 2007)

At the first time we have been able to see the structures in the solar atmosphere in three dimensions. This is extremely helpful for scientists who are studying various dynamical phenomena that occur in the Sun, such as solar flares and coronal mass ejections.

You can find 3-D STEREO images for example from

http://www.nasa.gov/mission_pages/stereo/sun/index.html

http://stereo.gsfc.nasa.gov/gallery/gallery.shtml

Even though the period for observing solar structures in 3D has been passed, the STEREO satellites give plenty of interesting observations. For example since we get measurements from two widely separated points we are able to study the large-scale structure of coronal mass ejections and the structure of solar wind.