One common question I was asking myself is how to convert a Microsoft Word format (doc) to a PDF file (.pdf). This way I can convert my resume and other word documents to pdf, so no one can alter my documents.
I found doc2pdf service which is absolutely free. Where I can convert my word (.doc) to PDF file (.pdf)
Doc2pdf is a free online service which enables you to convert Microsoft Word documents (.doc/.docx), Powerpoint (.ppt) and Excel files (.xls) into Adobe Acrobat PDF (.pdf) documents. All MS Office versions are supported, including Office 2007.
With Doc2pdf you can convert PowerPoint files to Macromedia Flash (.swf) too.
Give it a try and let me know other free service in comments section.