Wait, I think there's another way.
http://www.howtogeek.com/howto/12936/create-an-itunes-account-without-a-credit-card/
This might work.
To summarize that method (in case link gets broken later),
1. Download, install, and
open iTunes.
2. Click on
iTunes Store. Set the country to
USA. (according to some notes, this may work only with US location, not with other countries. Invent an address if needed, e.g. 123 Fake Street or 1-3 Infinite Loop, 95014 Cupertino CA.
3. Click the
App Store link on top of the page
4.
Select a free app to download.
5. There should be a pop-up asking to log in, or
create a new account. Create a new account. Click past terms and conditions. After setting your user details on the first page, click on continue. You'll be asked to provide payment details for future apps - the "none" should still be an option here.
6. After you finish setting up your account, you'll get a confirmation email.
According to the latest comments on that page, it still works with the newest iTunes (as there are comments from March 2011). The secret is to
download a free app as part of the steps above, so don't skip it.
(Note: I already have 2 iTunes accounts that I don't use; didn't test with creating a third one).
If you need any ideas for which free app to get, there are plenty to choose from. Utilities, research, games... pick any. You can always delete the app if you don't like it, and get more free apps that better suit you.
And there are some more notes of what work and what doesn't on that page.
( 