The “ECB” menu is the contextual menu that provides quick access to functions in libraries and lists via a drop down. By default it’s only attached to the “title” field but it’s fairly easy to add to another field in a Sharepoint 2010 library. I don’t see a way to do it using the browser so you will need Sharepoint Designer 2010.Open the site and your desired library view in “design view” in SPDSelect “advanced mode” from the ribbon.
Click an item in the column you want to add the menu to.
When the little arrow and “Common xsl….” dialog box shows up, check the boxes for “Show list item menu” and “Show link to item”.
Save the view page and check your library: