I think this is definitely a topic worth discussing. I know for our first book project, my concept of the phone book was purely accidental, (as I changed my background from pink to yellow) but I built off the foundation of the traditional yellow pages phone book we are used to seeing and put a spin on it or slant. haha. Anywho, when we were working on that I wondered if someone would have considered that as stealing someone else's work. I think there's nothing wrong with viewing someone's work and being influenced. I also think it's an internal and ethical thing when anyone, designer, writer, etc. blatantly takes someone's design and call it your own. As a writer I often read books or essays and am inspired by an author's writing style, tone, poetic and fluid description, etc. I welcome it and look to learn from it. Now if I happen to Google something and I see my words, verbatim, with no form of attribution, Houston, B-More, DC, we have a problem.
I think ripping off someone's work is a reflection of the designer, writer, it shows laziness and desperation. If you're a designer, let your work be influenced by others but let is also influence. The beauty of being designers and writers is that what you produce has your name on it. Like Aseloka said, it's a reflection on you. We can either be masters of the craft or James Frey :/
I don't know if I truly addressed the topic or question but I know I often turn to channels for inspiration, not to run with an idea but to allow it to be a brick along the pavement.