Printing to PDF is an awesome productivity enhancer that I think all computer users should be aware of. My favorite is CutePDF so I will talk about that one but several similar utilities exist.
CutePDF is a free utility that lets you ‘print’/convert ANYTHING to PDF. If you can print it, you can turn it into a PDF. This is an excellent alternative to anything Adobe Reader. It has some other great uses as well, such as storing offline (or archiving) webpages, saving digital reciepts and bills, and sending/uploading documents to websites or through emails.
When something is in PDF, it has a hidden connotation “don’t edit me!”. PDF is a standard document format nowadays, so if in doubt if recipients have MS Word/Open Office/whatever, PDF is the way to go.