Create a PDF with alternating pages from 2 PDFs using pdftk.

Create a PDF with alternating pages from 2 PDFs using pdftk. Taken from http://binarystatic.wordpress.com/2010/10/17/interleaving-two-pdf-files/

pdftk A.pdf burst output out%04d_A.pdf
pdftk B.pdf burst output out%04d_B.pdf
pdftk out*.pdf cat output AB.pdf