Over the years I have developed a number of interactive tools that I use in my classes. This is a tool that seems appropriate for VIPEr. Comments are always appreciated, and I am always interested in developing new tools if there is something you might find useful.
This tool allows you to look at how molecular orbitals change as the difference in electronegativities of the parent atomic orbitals increases.
NOTE ADDED OCT 2014: As Flick's site at Wellesley is not available anymore I looked in his archive website (http://www.flicksstuff.com) and found the final version of this web resource, and it is linked below. I have left the rest of the LO unchanged for archival purposes. --Adam Johnson, Harvey Mudd College