Distribute an app

Eventually, I want to distribute an excel app to about ~25 users. I read that one approach is to create the app as an add-in. That way I can password protect the code and so on. Not knowing much about add-ins I may be all wet here.

Is this a good approach or is there a better way? When doing VB 6 I would just create an exe but don't believe that approach is readily available with Excel '07. Am I wrong here as well?

Depends a bit on what your workbook does

You are limited to password protect with only "Add-ins" you can passowrd protect a workbook or worksheet also