Password manager on other computers

[Nem]

Recently I've been looking at using a password manager to handle my passwords (LastPass, keepass, dashlane etc.). One thing I dont understand is how they work when you need to login to a site on someone elses computer. Lets say you need to show your friend an email and need to login to gmail, but you only have access to their computer. How does a password manager work in a situation like that?

 

The software isnt installed on their computer, you wont have dropbox available on their computer if you need to sync a local password vault, you could store everything on a USB but there are going to be situations where plugging a device into some elses computer is a bit too intrusive (e.g. youre at a workplace that doesnt allow USB devices)

[Techicolors]

maybe use your phone? think lastpass and keepass have apps for android and iOS 

[Nem]

But what if say you need to log in to your dropbox to grab a file so you and the other person can work on something? Logging in on my phone doesnt seem ideal in that situation

 

Do password managers not offer a way to log in on someone elses device like this?

[RedWulf]

I think lastpass has a portable version, but you can keep lastpass on your phone and just view the passwords as needed, I'm sure other managers allow you to as well.