In case of UT2004 almost nothing had to be done. :) So from the ethical point of view this would be... unethical. That's because we also provide you with support, ability to download a game at your leisure (unless the publisher tells us to pull out something), fancy community, kwel site and the certainty that the game was properly tested and that it will work on XP/Vista 32/64bit. If you don't feel that we cna expect you and your friend to respect our work as well as IP rights... well... it's your choice.
We all know that it's my job to write something like that. I'm obliged to tell you that doing so would violate IP laws that exists in our countries and would make the whole thing a simple piracy and a theft. Morning today I've bought cigarettes. I had to because I'm a smoker and because I left the previous pack at home. And you know what? I've paid money for it. For me that's ethical. Someone had to work so I could get them and acquire cancer. ;]