OK. Didn't know where to put this exactly...
This is a fun way to mess with your friends! All you need is a few minutes alone with their computer to edit the EULA they get. Go to the following path;
Computer > Vista (C: ) > Program Files > World of Warcraft > Data > enGB/US
Ok. In this area is a folder called "eula". Open it with notepad and edit away! This SHOULD show it up again next time your mate opens WoW, if not do the following;
Go back to your main WoW directory and open their WTF folder. In that folder is a file called "Config". Open it up. Scroll sideways until you see something called;
readEULA "1"SET
(It should be on the top line)
Change that to a zero, save it, then change it back to a 1 and it should show up next time they run WoW.
Great fun to mess with your mates