It's a hack because need to modify K2 and Joomla! core files. All files are attached to this post, all changes are commented in files.
K2 is a powerful extension that allows for incredible control of your Joomla content. This module is a modification to the standard K2 content display module. Rather than define the content you want to display in the module, this module pulls the item data from the current item being displayed.
This allows you to expand your layout options since you can now display part of the item content in the main content display area and other bits of content in the module positions. You can even load more than one module per page to deliver highly complex layouts with the content exactly where you want it!
The module supports multiple instance on a single page so putting item content exactly where you want it is no problem. K2 Plugins are triggers so the module can also be used to display the K2Mart buy now box in any module position.