Dropbox has finally implemented their version of two-step verification and if you have a Dropbox account you really should enable it. If you don't have a Dropbox account I suggest you first get an account and then enable two-step verification.
To turn the feature on, you’ll have to have the most up-to-date beta desktop version of the Dropbox client. Once you have that, you can hop over to the Dropbox website to set yourself up in the beta and turn on two-step verification.
The two-step verification implemented by Dropbox works similar to the way Googles works. It can be a pain to manage at times but the alternative of having your account hacked and any personal (or non personal stuff) you have stored on it tampered with is far more of a pain.
Do yourself a favour, activate this as soon as possible.