How to create a single page PDF file out of multiple EPS files with GhostScript

Here's a variant of un2up, which uses Python with the pyPdf library. Note that you need at least version 1.13 (prior versions did not support scaling). Untested.

#!/usr/bin/env python
import copy, math, sys
from pyPdf import PdfFileWriter, PdfFileReader
input = PdfFileReader(sys.stdin)
output = PdfFileWriter()
for p in [input.getPage(i) for i in range(0,input.getNumPages())]:
    p.scaleBy(math.sqrt(2))
    q = copy.copy(p)
    (w, h) = p.mediaBox.upperRight
    p.mediaBox.upperRight = (w/2, h)
    q.mediaBox.upperLeft = (w/2, h)
    output.addPage(p)
    output.addPage(q)
output.write(sys.stdout)

A function I use all the time to do exactly this. Just make sure the pdfs sort properly in sequence in the expansion.

tp="/tmp/tmp.pdf"
td="/tmp/data"
for i in *.pdf; do
    echo "Bookmarking $i"
    printf "BookmarkBegin\nBookmarkTitle: %s\nBookmarkLevel: 1\nBookmarkPageNumber: 1\n" "${i%.*}"> "$td"
    pdftk "$i" update_info "$td" output "$tp"
    mv "$tp" "$i"
done
pdftk *.pdf cat output myBook.pdf