Column order

Hello,

It is often convenient to have columns of a table in certain order (as shown
by psql or most GUI database explorers, it also affects INSERT's
without columns specified behavior) so as to most significant columns
to
come first, semantically close columns to be grouped etc, while the columns
might be added to the table in different order during development
process. So, the question is - is it an acceptable way to play with
pg_attribute's attnum and set it to needed value
or recreate the table is the only
way? On the related note - should the columns necessarily be numbered
from 1 up with the step of 1?

Thanks,
Viatcheslav