Pogoplug has already moved to the cloud. Now, it's coming back down to Earth. Today, the company unveiled its latest "cloud expansion device," known as the Pogoplug Series 4, pictured above. As the fourth incarnation of Pogoplug's original device, this box effectively allows users to host their own unlimited storage, for those moments when 5GB (or even 10GB) of cloud space just won't cut it. With Series 4, you'll be able to hook up your HDD through one of four different connection ports, including two USB 3.0 inputs, one USB 2.0 port and an SD card slot. The model also features plug-and-play support for Seagate GoFlex external drives, or any other USM-compliant products. It's available now for $100, so head past the break for more details in the full PR.