Do you know of a way to display a message on every page when a user had not changed thier default image in there profile. Once there profile has changed then I no longer wish to show the message.
There wouldn't be anyway to do this without writing custom code. If going the custom code route you could create a Visual Studio Web Part. Have it check the profile of the user to see if it is blank or null. They display the message in the web part. Here is one way to access the profile picture through code: http://mysharepointwork.blogspot.com/2010/11/sharepoint-2010-show-user-profile.html