PDFCreator is a software allows you to create PDFs from any Windows program that can print.

When you install PDFCreator you will be able to print to virtual printer that will save the output to a PDF file. The  document than can be read on any computer with Adobe Reader or any other PDF reader. Best of all PDFCreator is free and open-source.You can even use it commercialy. Main features:

• Create PDFs from any program that is able to print
• Security: Encrypt PDFs and protect them from being opened, printed etc.
• Send generated files via eMail
• Create more than just PDFs: PNG, JPG, TIFF, BMP, PCX, PS, EPS
• AutoSave files to folders and filenames based on Tags like Username, Computername, Date, Time etc.
• Merge multiple files into one PDF
• Easy Install: Just say what you want and everything is installed

Homepage: http://www.pdfforge.org/products/pdfcreator