Using Upper Case Letters in Web Addresses

Are URLs Case Sensitive?

Does it matter if it capitalize web addresses? Based on this article from wisegeek.com it doesn't matter for domain names, but it does matter for pages on a website.

So, if I want people to be able to read my site name more easily on print materials or in other references, I can use capitals to make it easier to read. Examples: BloggingForWriters.com or LexicalLight.com. However, if I'm building a website or naming a blog page url I need to stick to lowercase.

Good to know.

(BTW, I'm trying out the Reblog feature on Typepad.)