Fes: I admit I'm not up to par on british copyright law, but I'm pretty sure your friend is wrong there. The UK has the same "automatic copyright" that we in the U.S. do. That is, a work is protected by copyright from the moment it is created. You do NOT have to register it. (Patent law is different.) Registration does entitle you to more damages, and makes the lawsuit work differently, but you're still protected, even without it.
Mune: The bit I'm not sure about is that you're not a UK citizen, and the work was first "published" in the U.S. When I think about that more, I believe you have to be covered under US law (you should lookup the US version of that CC license.) Since the violation is happening abroad, any protection you're going to get is from international law. The main part of that is the
Berne Convention In fact, the reason you do NOT have to register a copyright is the Berne Convention. The U.S. didn't sign on for more than a hundred years, specifically because we DID require copyright registration. However, since 1989, anything you create is protected by copyright from the moment you put it in a tangible form. (Ideas alone don't count.) From there, the Berne convention requires that all member nations recognize each other's IP laws, and thus, you're protected in Britain as well.
As to the legitimacy of the CC stuff. Your work is ALREADY copyrighted without it, so it's not at all like the "Stamped Addressed Envelope" thing (which claimed to exploit a bit of postal law which declared stuff sent through the mail as "published materials.") What the CC does is provide a basic legal document to enable you to set the terms for other people's use of your copyrighted work. It doesn't add protection to your rights, it actually gives some of them away (such as the ability for others to make copies) but it does so conditionally. In the case of the one I linked you, those conditions require it not to be used commercially, to always credit you with original authorship, and to likewise license derived/collected works under the same license. The reason I suggested the CC is that rather than just saying "you can't use it, it's mine, give it back" (which you have every right to do already) you're saying "I said you could use it, if you did certain things, and now that you HAVE used it, I expect to to follow through on those other things." It doesn't in anyway grant you a stronger case, it just provides specific details (and the legal language explaining them) for you to complain about and demand. It's more precise threat, not a more powerful weapon.
You mention putting other works under the CC license. If you're looking to simply protect them, there's no need of a CC license at all. You are ALREADY PROTECTED as soon as you create them. The CC is about giving your work away... going from "All Rights Reserved" (which is default for anything you create) to "Some Rights Reserved." I use it for stuff I create, like the Xepher.net code and designs, because I believe that's the sort of thing people should be sharing with each other and improving, not hoarding for themselves so everyone has to reinvent the wheel. On the other hand, I write a lot of short stories, some of which I hope to one day get published. These are not under the CC, as those are things I don't want other people sharing or changing or reworking. I also want to keep my chance of one day making money from getting them published. Not that YOU can't still publish/profit/etc from anything you put under the CC (as copyright owner, you can do whatever you want, the CC license just says what OTHER people can do), but there's little point in buying the right to publication (which is what a publisher pays you for), when it's already been given away for free. Anyway, long point is, if you want to share your work for others to use in some way, the CC is the way to go, with plenty of different license options so you can choose WHAT people can actually do with your stuff. On the other hand, if you just want to protect it and keep it all yours, then there's nothing at all you have to do past pushing "save."
