As you probably heard SharePoint 2013 Preview has been released. There is number of cool features available but there is one that’s super simple yet so very useful. I am huge fan of DropBox, this simple application allows you to sync your folders to the cloud. Now you can do the same with SharePoint 2013, no special requirements to configure this.
Figure below shows a document library synced to my computer. All the changes are propagated back and forth. Very cool and helpful feature.
Update 2013-04-04: I have updated this screenshot to match SharePoint 2013 / Office365 RTM.