This technique is most often used for landscapes, but can be used for other things as well.
Because I lack a fisheye lens (or any lens wider than 18mm), I decided to use a stitch at Grant Imahara's speech earlier this week to show the size of the crowd. (click to enlarge)

In this room, there were 850 seats. That is a fair amount of people, especially for an on-campus speaker (many of whom draw around 100 people). There were people standing the back and sitting in the isles, and 150 people were turned away at the door.
I knew this shot wouldn't run in the paper, but I also knew that I couldn't capture the sheer size of the crowd in any other way with the equipment that I had (or have). I figured it might run online, so I did it anyway. Whoever is in charge of The Lumberjack online rejected this photo, but luckily for me I don't need them to get my work out into the world.