Do you need a way to create PDFs from various programs on your computer like Word, Excel and PowerPoint? Then checkout CutePDF Writer. It's FREE and doesn't have an annoying trial period, watermarks, or limited functionality.
Once you install it just use it like a printer. Select Print, choose Cute PDF as your printer and then click Print. It'll ask you the filename and location you want to save the PDF it creates. Great little utility!