tools to manipulate PDF document?

[wcc]

Thanks Justin.  Yes, I had tried pdftk before (could be the current
version though, since it has not been upgraded for a while).  But
somehow it was quite slow when I tried merging, or spliting PDF
documents when compared with Adobe Acrobat, especially if the number of
PDF to be processed is large.  I wonder if anyone had similar
experience.

Justin Ezequiel wrote:
> have you seen http://www.pdfhacks.com/pdftk/