Hi Developer Network :)
I've created a module for silverstripe 3.0, it is called gridcontentmodule.
This module creates a new Fieldtype "GridcontentField" and a new database fieldtype "GridcontentFieldText"to store the data.
Once, you have added the new fieldtype to your page, you get a visual tool to create content, that is arranged in rows and columns for a responsive webdesign. Every row can hold another amount of columns. You can also change the order of the rows. After saving this gridcontent, you can loop over the rows and columns in your template.
The module uses the framework zurb foundation as default, but you can use your own responsive front-end framework, since the css-classnames of the rows and columns are fully configuratable.
You can find the module on github:
Please have a look.