These days, the first thing I do when preparing a lecture is to scour Molecular Workbench for useful animations, as I have discussed in a previous post. True to form MW did not disappoint, and I put together the following set of MW slides (note: you need to install MW first before clicking on it).
The screencast above shows how I used four of the slides to illustrate the concept of tunneling and and how it applies to STM.
Once again, I found animated simulations in general, and MW in particular, invaluable in bringing across complex concepts. And once again MW did all the hard work.
2012.09.01 Update: I made a few more screencasts of parts of my lecture