Folder Share. Your files anywhere. But not on top of that stupid rock, I bet. Anyhoo, there’s a free basic plan and a subscription one with more features. Looks neato. [Thanks to Rob for the pointer.] 

FolderShare allows you to create a private peer-to-peer network that will help you to synchronize files across multiple devices and access or share files with colleagues and friends. You no longer need to send large files via email, burn them to CDs/DVDs and mail them, or upload them to a website. FolderShare allows you to share and sync important information instantly with anyone you invite, making it the perfect solution for personal or small business use.