"Think" is a motto made famous by IBM's founder Thomas Watson. It began its cultural live as a motto of National Cash Register, where Watson worked as a young man. Watson left NCR in the wake of some legal embarrassments and ended up running CTR, which became, in the fullness of time, IBM. "Think" was one of the NCR cultural artifacts Watson took with him on his long and eminently successful journey.
It is rumoured that some people at IBM made fun of the "Think" motto by altering it to read "Think or Thwim".
from http://www.tech-news.com/infoperspectives/i9801/quant.html
Updated May 11, 2002.