Another nice thing about Acrobat files is that you can set security. So, for example, you can allow printing, but not changing the text or images. I once had a well-meaning soul rewrite a portion of a little manual I wrote for work, causing a narrowly averted disaster with a client. After that experience I always set security. Just make sure you use a password you won't forget AND save at least one unprotected copy of the file. Of course, it's Adobe, so Acrobat is not cheap - but full of features and useful once you've got it.