In the previous versions on ASP.NET MVC, you could use ModelState.AddModelError("**_FORM**", "error") to make an error on the form-level instead of a property-level. This seems not to work anymore with the new RC of ASP.NET MVC 2.
Is there another way how to do it? I use <%= Html.ValidationSummary() %> at my View-file...
 
                        
I personally use
AddModelError(""- I don't know where does _FORM come from? - andValidationSummary()is no black magic - I use my own helper instead that, for example, includes specific (user-specific) exceptions messages into output. The helper is very easy to write - a simple foreach loop over ModelState - so you may consider writing your own one. There you're free to show form-level, property-level, or whatever you like.