GnuPG in cybercafe

[Angel Vicente]

Hello all....

I'm very newbie at GPG, I'm a Debian user for some years ago, but I have 
nothing to see with GPG until now, I think I understand the main flow and uses
of GPG, but I have a doubt:

suppose a group of friends, they want sign and/or cypher their email and files,
almost of them are Windows users, all have email accounts in Google, Yahoo, MSN,
etc, I think I could teach them to use Thunderbir+Enigmail or other..., but:

there is one that hasn't got PC or laptop or anything so, he uses PCs in 
cybercafes or public libraries, well, what about some portable apps in USB?,
answer: perhaps could be a good idea, but what about keyloggers in public 
computers?, I'm worried about this.

I've tried with Neo Safekeys, but seems doesn't work with pinentry from GPG4Win,
so what can we do?, is there a solution for use GPG in public PCs and for
possible keylogger at the same time?

Best regards and thanks in advanced