Here is the fisheye camera rig and preferences file for Blender 2.6x+.
Note: This rig is for the Blender Internal Renderer and also includes a cycles fisheye camera in a separate scene. You will need to change the scene to "cycles-fisheye" to use the cycles fisheye camera. (You can also use Blender 2.65 and up to render fisheye with cycles natively.)
(Edit 13 February 2013: File updated.)
0. Click link above to download.
1. Launch Blender.
2. File > Load Factory Defaults.
3. Open the downloaded file.
4. Adjust UI settings (window positions, etc, if needed).
5. File > Save User Settings.
6. File > New.
The fisheye camera rig is licensed under your choice of Creative Commons Attribution-Share Alike 3.0 or GNU GPL v3. (The license applies only to the tool provided, not to the work you create with it. Your work is your own.)
Here's a brief overview of the fisheye camera rig (slightly outdated):
Here's how to add the rig to an existing scene:
The friendly UI (no fisheye camera rig):
Production Team Supervisor for Clark Planetarium (clarkplanetarium.org/distribution)