Inventing DropBox isn't exactly new. Lots of software products can synchronize files. Remember XDrive? What about that Briefcase thing in Windows 95 that almost no one knew how to use? And all these: http://en.wikipedia.org/wiki/File_synchronization, http://en.wikipedia.org/wiki/Comparison_of_online_backup_ser...

DropBox did make an easy-to-use service, and also got the timing right. Owning more than one computer is no longer just for geeks.