I love dropbox. I use my 2gb free account to automatically load my website backups so I always have the latest copy available if things go wrong.
I also use it’s public folder feature to make certain documents accessible to clients which they can then easily download.
Apart from simply storing data and files or photos, here are a few other ideas;
https://zapier.com/blog/dropbox-hidden-features/
I reckon Dropbox is brilliant. It’s easy, smart and keeps me sane!