Dropbox is a free service that lets you bring all your photos, docs, and videos anywhere. This means that any file you save to your Dropbox will automatically save to all your computers, phones and even the Dropbox website.
Even if your computer has a meltdown, your stuff is always safe in Dropbox and can be restored in a snap. Dropbox is like a time machine that lets you undo mistakes and even undelete files you accidentally trash. Your Dropbox is always ready for action from the Dropbox website too
As of October 2011, Dropbox had more than 50 million users.
Know more about Dropbox, click here