How do I do a pivot table in Numbers?

I can't find any equivalent of the Excel Pivot Table or Open Office Data Table features. I'd like to sum up my data grouped by values in various columns.

For example, if I have

A       B       C
red     left    2
red     left    3
green   left    4
green   right   4

I want to be able to get

        red     green   all
left    5       4       9
right   0       4       4
all     5       8       13

Assuming the tables are named Original and Pivot, the cells in Pivot are filled using this formula:

=SUMIFS(Original::$C, Original::$A, "="& $A2, Original::$B, "="& B$1)

i.e. sum values in Original::$C if

• corresponding value in Original::$A = value in first column of Pivot
• corresponding value in Original::$B = value in first row of Pivot

The 'all' values are just simple sums of those rows or columns.