The Edit Control Button (ECB) aka the context drop-down menu that appears for lists and libraries, as shown in the image below, is the way you can execute built in and custom actions on list and library items.
A question that many people wonder about is: how can I move this menu so it appears on a different field instead of the default one?
Well, wonder no more! Watch the video below to see how it's done. One catch though: you will need SharePoint Designer 2010 (available for free) to make the change.
Enabling and Disabling ECB menu on list/library items