Dropbox is a simple idea. So simple in fact I am surprised it took until 2011 for this to become mainstream. I keep code snippets, books, documents and a few tunes in my Dropbox. I then have access to all of them on my laptop, mobile and tablet in a matter of clicks.
It reminds me of an extension that you use to install and it would store files in your free email allocation that Google gave you. For some reason this either died or was blocked by Google. Now there appears to be a mass scramble between Apple (icloud), Google (Gdrive – coming soon), Microsoft (Skydrive) and Dropbox.
Why didn’t Microsoft buy Dropbox and just keep it exactly like it is I do not know. It is an essential tool to Windows.