It makes me feel a bit sick to recommend a Symantec product but PGP Desktop is pretty much the standard crypto product. You can integrate it into your mail, use

It makes me feel a bit sick to recommend a Symantec product but PGP Desktop is pretty much the standard crypto product. You can integrate it into your mail, use it to share on a local network or encrypt files and share them any way you like (dropbox, email, carrier pigeon). The Free alternative, GPG4Win is pretty good for Windows (or GPG for other platforms) but might be less intuitive for the less technical, and you don't get whole disk encryption thrown in. You're not going to be able to access GPG/PGP from a phone, but if you're using something like Google Apps for domains you can ensure that everything's encrypted in transit over SSL.