Select the format you want to copy and press Ctrl+Shift+C. Select the
destination and press Ctrl+Shift+V.
You can use the Format Painter tool (on the standard toolbar in 2003,
or on the Home ribbon in 2007) to do the same thing. If you expect to
paint the same format in several places, double-click the button to
make it stay active; press Esc to turn it off.
The keyboard shortcuts have the advantage that the format you copy
remains available to be pasted multiple times, even though you may do
other editing in between.