The Hubble Law Lab has moved and has been modified to allow for a server-independent measurement of pixel values that will lead to the distances and recessional velocities of 18 galaxies for the short version (galaxies have been pre-selected and instructions abbreviated) or 27 galaxies for the full-blown lab with detailed step-by-step istructions.

Hubble Law Lab, Pre-Selected Galaxies

Hubble Law Lab, Director's Cut