© Hal Berghel 2008 . All rights reserved. All requests for reproduction and/or distribution of this electronic document should be submitted via Email to the author (hlb at berghel dot net).

This is a draft version (preprint) of material which was later published in substantially the same form in my Digital Village column in the Communications of the ACM. The published version is a copyrighted feature of Communications of the ACM. All requests for reproduction and/or distribution of the published version should be directed to the ACM.