What's the difference between Databinder.Eval and Container.DataItem?
Eval is one-way binding and Bind is for two way binding. Using Eval allows you to get the content into your page, but ASP.Net will not be able to put it back into an object for you.
The Eval method is just shorthand for DataBinder.Eval. Also, Container.DataItem("Property") is effectively the same as the Eval method except for when you want to return the value of a "path". For instance you can call Eval with a dot-separated "path" to a public property that you want the value of, but I do not believe you can do this with Container.DataItem("Property").