Neat way of using R for pivoting?

Gabor Grothendieck wrote:
...

The fact that Excel has both an interactive interface and a script-based
interface whereas R has only a script-based interface puts it ahead, not
behind, R in at least some respects.

Sorry, but I can't resist:  That very much depends on if
you are doing something that is appropriate to be done
in a spreadsheet.  The set of tasks appropriate for R is
very much larger than the set appropriate for Excel.

http://www.burns-stat.com/pages/Tutor/spreadsheet_addiction.html

I certainly don't want to be an apologist for Excel but I would
not asses its domain of applicability to be a subset of that of
R.  I agree with most of the points made in the link you cited 
but its mainly concerned  with stretching the use of spreadsheets 
to situations where R would be better  

At the same time the domain where spreadsheets are appropriate 
and preferable is very large and probably exceeds the domain where R
is preferable to Excel due to the fact that financial, accounting
and budgetary work done by every organization is mostly in the domain
of applicabilty of Excel.  Also I think the link overstates the case,
at least in reference to Excel, since some of the criticisms can
be overcome using Excel's scripting capability.