Bad Coriolis
This great page tells why the Coriolis Effect does not modify the direction that water flows down a drain.

Coriolis Effect
A bit of history combined with great graphics of the effect.

Coriolis Effect
A nice scientific explanation of the effect.

Coriolis Force
A simple explanation along with animated graphics to show the effect.

Coriolis Force Debunking
This page attacks the urban legend.

Coriolis Poll
From your Guide - what do you think?

Which Way Will My Bathtub Drain?
This question and answer shines light on the common misconception.