If you only need to turn documents into PDFs like Word or Excel files, use PrimoPDF. Installs itself as a printer, so all you do is print to the PrimoPDF printer, which then makes a PDF. Unless you're going into forms automation or advanced stuff like watermarks, adding ActiveX and java to your PDFs you don't need the full Acrobat product.

It's like using the full edition of Photoshop just to resize a JPEG or a GIF.