PDF Joiner - This online tool allows you to join several PDF documents into a single file, free of charge.
DottedSign - The Best E-Signature Solution for Your Business
PDFTK Builder - PDFTK Builder is a free graphical interface to for PDFTK, making it much easier to use.
DocuSign - Try DocuSign's interactive signing demo now! Send yourself an electronic document to digitally sign using our e-signature service.
PDFChef Merge PDF - PDFChef Merge PDF is an online tool that allows you to merge multiple PDf files into one quickly and securely.
LibreSign - O LibreSign (assinatura eletrônica) permite que documentos sejam assinados de forma segura e com validade jurídica.