I have just seen some photos of the sun which someone did from their own backyard.
Not sure what sort of equipment he used, but what could I use to photograph the sun with my DSLR? I have a Nikon D5100
Those pictures seems to be taken trough microscope with H-alpha filter. Most of them are converted to black and white.
There is a whole website dedicated for solar photography: http://www.hydrogenalpha.com/
Here is some info about H-alpha filter: http://en.wikipedia.org/wiki/H-alpha
To take similar pictures, you will need a telescope, F-mount to telescope adapter and an H-alpha filter. Some of the telescopes are built for observing sun and have an H-alpha filter built in.
Alan Friedman, the astronomer featured, gave a TEDx talk late last year where he spoke about his inspiration for making these pictures. (Here's the link for the video: http://youtu.be/LTtTfCwkIW0)
In the video, he shows some of his gear.
He has two telescopes he's using. One is a refractor that probably has a built-in Hydrogen Alpha filter in place for exclusively solar work. Lunt and Coronado are two manufacturers that make these specialized scopes. Another appears to be a medium sized catadioptric (either schmidt cassegrain or likely a maksutov cassegrain). This latter scope has what appears to be a shiny glass filter that is removable. This is also likely to be the scope that he uses for planetary work.
Lastly, he shows the camera he uses. He's using a Point Grey Flea camera (likely a Flea 3 since he mentions 120 frames/sec). These are used to generate a stream of short exposures in a video format. The best frames are culled from the video as an example of "Lucky Seeing" and these are used to make a single, ideal image.
You can employ this technique with a DSLR. If your model can stream raw video (not a downsampled version) then it can work well. If it can't you may still use bursts of single images that are processed afterwards. The computing resources needed for processing a stack of DSLR images vs a video feed are significant.
Hope this helps!