I would suggest not using them if you have to type in any password. I work as a network security guy and have a masters degree in security, so I'm paranoid enough to suggest this.
Reason is, regardless if there is a keylogger, if someone put a packet sniffer on one of the computers, they will most likely be able to grab all the information being transmitted across their network. The copy/paste or typing random characters would not circumvent this. I did this at a hotel that I was attending a hacking class. Interesting what I found.
Edit: When I say "their", I mean the hacker. Once a hacker has something like a keylogger on a computer, they now "own" that network.