To make half-size folded-page booklets, do:

can hpf-booklet.ps
psbook hpf.ps | psnup -2 | pstops "2:0@1.0(0,0),1U@1.0(1w,1h)" \
   > hpf-booklet.ps
ps2pdf -dPDFSETTINGS=/printer hpf-booklet.ps
lpr -P theoryh-dup hpf-booklet.ps

The PDFSETTINGS option above prevents ps2pdf from auto-rotating the
pages.  Alternatively, can do:

ps2pdf -dAutoRotatePages=/None hpf-booklet.ps

If the booklet gets too thick, you can break up the folded pages into
"signatures", by replacing the psbook command above with

psbook -s16 hpf.ps ...

which breaks it up into sections of 16 logical pages (4 physical pages)
that can each be folded separately before stapling them all together.

--------------------------------
An alternative to using the pstops command above is to do:

psbook file.ps | psnup -2 | lpr -h -C tumble -P theoryh-dup

The "tumble" option is the key, as otherwise the reverse pages come out
upside down.  (This is equivalent to "binding on the short side of the
page" instead of the standard "long side of the page", and so tumble is
needed for printing 2 logical pages per physical page and then folding.)

theoryh prints with a nicer darker font than theoryne.