Hmmm. Recalled you can do this using MvcContrib.
So I went and added a reference and do a call like this (that worked in an older MVC 1 project)
Code:
// return this.RedirectToAction(x => x.ContactSuccess(model));
return this.RedirectToAction<PublicController>(x => x.ContactSuccess(model));
Now, when I hit that line I get told that Mvc's dll cannot be found. Uuurgh..this is an MVC 2 project created in VS 2010!
Server Error in '/' Application.
Could not load file or assembly 'Microsoft.Web.Mvc, Version=2.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.Web.Mvc, Version=2.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified.

Source Error:

Line 32: {
Line 33: // return this.RedirectToAction(x => x.ContactSuccess(model));
Line 34: return this.RedirectToAction<PublicController>(x => x.ContactSuccess(model));
Line 35: }
Line 36: return View(model);