Live Mesh - "hands on" video
An interesting video to watch if you need an introduction to Live Mesh. Now in technical preview, to me it is like a coming together of FolderShare and Skydrive. With tight desktop integration, it allows you to synchronize files and folders between different devices and also a "virtual storage device in the cloud". The cloud storage is currently limited to 5Gb but you don't need to use it - you could just use Mesh is as a way to backup files between machines, perhaps with friends and family, and access you files from different locations.