FarCry has now been crossed off of my purchase list.
Ok, but if that's all it took then you must not have been very interested. Loads of people already through the same "hassle" just for GunBound!
Perhaps further clarification is in order:
To play single-player or on a LAN, you do not need to enter ANY information.
The first time you play online, you need to enter your CD key (you do not enter it when installing) and your username and password.
To play online again, you need to enter your username and password only. The game used to give you the option of savving your username and password, but it does not offer this feature any longer.
Personally, I don't play the game online much. The multiplayer is fun, for sure, but I recommend the game for its single player mostly, and because it's fun and easy to modify the game.