Stunad,
Please ignore the entire post from "LA Law" - a friend of mine is just playing tricks with you.
When you create some unique material (code/art/music/etc), you automatically have the copyright to that piece through international copyright laws. Its still good to include such a "Copyright (c) [year] [your name]" message to notify everybody that you claim the copyrights and make sure that noone can say "Hey, I didn't know" when you face them in court after they have pirated your game.
The references to IonStorm's product Daikatana is also just bogus - please disregard the entire post.
What you might be thinking of is Trademarks (TM) and Registered Trademarks (R). You can (and should) claim Trademark ownership to the name of your company, the name of your game, slogans you create, etc. You don't have to perform any action other than including a TM sign after the IP's in question (IP = intellectual property) to claim the ownership of the trademarks.
However, you cannot claim to have a Registered Trademark (R) without actually registering the trademark with the government. This a somewhat complicated issue and you should contact a lawyer or something to handle such a process for you. The trademark will be checked against national and international registers of other trademarks, and you can be sure noone else can claim to have the same Registered Trademark (R). When you build your empire of world domination, you migh find out that someone have been using the same name as a Trademark (TM) and if he can document that he has been using it way before you started using it, he might have a right to continue using it is his local marked - but he will never be able to build a world dominating empire himselves, using the same name.
Regards,
Chez
