One of the sad things is that pdftk hasn't been updated in ages, and doesn't support current versions of PDF. I.e., it may bail out if it has to handle PDF 1.6+ documents. It has been a great tool, but increasingly I can't use it any more to handle Acrobat-created documents.
Downloading iText is fine and dandy, but an easy CLI interface like pdftk that we'll find in major distributions is severly missing. Or maybe it exists, and I just don't know about it -- please correct me... ;-)