Hi James,
GeoNet is our new forum site where you can share, chat, and collaborate on any technical questions or projects you may be working on. I am thinking what you were after is our new Open Data functionality with ArcGIS Online. Here is a link that describes Open Data:
ArcGIS Open Data Help | ArcGIS
This requires that the organization with the data has ArcGIS Online and configures the Open Data site to share their data.
Please let me know if this helps!