The problem with this is getting the charts all the same size.
Here's my instructions:
http://lilt.ilstu.edu/jpda/charts/ch...p%202.htm#Side

But I agree the pie charts are a poor choice and two pie charts are
three times as bad as just one.

As for when to use cone, donut and other fancy charts, see tip three
on this page:

http://lilt.ilstu.edu/jpda/charts/ch...Chartstips.htm