ASP.NET MVC : how do I return 304 "Not Modified" status?

ASP.NET MVC 3.0, IIS 7, .NET 4

I have an action that returns data that seldom changes (almost static).

Is there an easy way to:

1. return 304 "Not Modified" from action;
2. include "Last-Modified" time stamp in the response.

I use return Content('my data'); for action result.

Basically I want an easy way to do what is talked about in this article : http://weblogs.asp.net/jeff/archive/2009/07/01/304-your-images-from-a-database.aspx