Rotation of Sun and Planets
The rotation period of a large body circled by one or more satellites can be calculated theoretically.
http://www.geocities.com/saeles/planetsrotation.htm

BackupAssist
Software designed to make it easy to implement tape backup rotation strategies easily. It provides scheduling, email notifications, and industry standard media rotation schemes.
http://www.backupassist.com/BackupAssist/

Pipelined phase-rotation FFT
By David O'Halloran. The Welchel phase-rotation FFT is a new form of the fast Fourier transform (FFT) that replaces data movement at runtime with equivalent multiplications by precomputed constants. The result is an FFT that is easy to pipeline.
http://www.cs.cmu.edu/afs/cs.cmu.edu/project/iwarp/member/fx/public/www/phase1.html

Electromagnetic Rotation
The experiments of Oersted, Faraday, Ampere, Sidorovich on electromagnetic rotation
http://sidam.at.tut.by

International Earth Rotation & Reference Systems Service
The NASA Jet Propulsion Laboratory IERS Special Bureau for the Oceans collects, calculates, analyzes, archives, and distributes data relating to non-tidal changes in oceanic processes affecting the Earth's rotation, deformation, gravitational field, and geocenter.
http://euler.jpl.nasa.gov/sbo/

Heavy Rotation
For business software, faster-cheaper can be better too.
http://www.acm.org/ubiquity/views/w_fiefer_2.html

SONNROT
Ermittlung der Rotationszeit der Sonne.
http://www.zum.de/Faecher/A/Sa/LB6/A10G.HTM

Daily Rotation
DAILY ROTATION, Tech News, current news headlines from hundreds of tech related sites, science news, web based RSS reader for tech headlines from hundreds of sites
http://www.dailyrotation.com/

AllStarInvestor.com
AllStarInvestor.com
http://www.allstarinvestor.com/

3D rotate
360-degree 3D object rotation in Flash using images - Flash VR tool
http://www.yofla.com/flash/3d-rotate/