Floating-Point Precision and Numerical Error

A while back Greg challenged me to look into numerical error diagnostics.  I still don't have a short answer, and the example he posed at that time (drift in orbital motion solutions) doesn't have a trivial solution.  However, I would be willing to work up this numerical error workbook that I created for UIUC lessons on HPC and contribute it to SWC if people feel there's a place for it.

This notebook covers floating-point precision and truncation error, and has a section on modified equations (the ideal approach to numerical drift, in my estimation) and a mention of Kahan enhanced-precision summation.  The last section in particular is currently sparse on practical examples, and there are no exercises.  Right now, I spend about twenty minutes or so on this with grad students with some prior programming experience (but little to no CS background).

What do you think?  Is this worth working on for inclusion or does it fall beyond the ken of SWC?