In my last post, I mentioned that I will describe the plan protection. So... here it goes...
First of all, there are two ways to protect your project plan:
1) Protecting from unauthorized access
2) Marking the plan as "Read-only"
Both ways require that you enter a password before saving the project plan (Save as->Tools->General options).

You can also check the "Read-only recommended" checkbox (as show in the picture) if you would like that users get a read-only recommendation windows when they open the project plan.
L.
This morning I received an email from Mark Walhimer. I'll copy/paste his text, 'cause I'm lazy :)
Quote: "Thanks for the great blog, lots of good information. Do you have any suggestions about sharing Microsoft project schedules with multiple people without using sever edition? Thanks for the great blog!, Mark"
First of all, thank you Mark. It is very nice to hear that this blog actually helps people.Sharing the project plan is something that everybody figures out for themselves (unless you have the Project Server). I use to do it either by using some kind of version control system (VSS, CVS etc.) or by communicating with my project teammates (verbal, email…).
Of course, if you don’t other people to mess up your project plan, you can always set the password on write permission. This way nobody can edit the project plan without entering the password. (I’ll write a blog post about this as soon as can).
I hope Mark, that this helps you in some way. If not, leave a comment and we can discuss it further. Of course, if anyone else has a better way (there must be someoneJ) please speak J
HTH,
L.