I just discovered sshpass and saw some comments of people complaining that there's no good use case that justifies it. Well, I have a use case. That's in fact what made me search about the theme and found it. I created a user on a machine and I can't remember which password I used, but I know it's probably one of a small list I can think of. The list is composed of variations of the same string, in a way that I could generate with a program. It would take me time to try all the passwords by hand, so using sshpass make things much easier:

$ generate-password > pass-list
$ for i in `cat pass-list`; do sshpass -p $i ssh host; done