DSLR Bracketeer: http://www.milosparipovic.com/dslr-bracketeer.html
A handy piece of Windows software to drive the motor on a Canon EOS dSLR autfocus lens and take a series of photographs for stacking in Helicon Focus or CombineZ.
This is a much cheaper (free!) alternative to a high-quality focusing rail.
The drawbacks are: 1. it needs a PC, so really only indoors and 2. the lens must have a focusing motor so wouldn't work with a microscope or the MPE-60.
Use at your own risk, of course!