Working with C# Anonymous Types

I am calling a method that returns a List variable that contains a c# Anonymous Type objects. For example:

List<object> list = new List<object>();
foreach ( Contact c in allContacts ) {
    list.Add( new {
        ContactID = c.ContactID,
        FullName = c.FullName
    });
}
return list;

How do I reference this type properties in the code I am working on like for example

foreach ( object o in list ) {
    Console.WriteLine( o.ContactID );
}

I know that my sample is not possible, I have only wrote that way to say that I need to identify each property of the anonymous type exactly.

Thanks!

Solution:

Not just one of the answer is correct and/or suggest a working solution. I have ended up to using Option 3 of Greg answer. And I learned something very interesting regarding the dynamic in .NET 4.0!