Service/App for viewing a Webpage as hex straight off the wire?

Are there any tools/websites/utilities for viewing a website in hex as it comes strait off the wire?

I'm getting some strange non-printing characters back from somebody else's C++ code and I want to identify the characters to find out where they are comming from.

I'm concerned that writing the file to disk messes with the characters that are written out (I think that this may only be true in the case of saving it with a text-editor, but I'm not entirely sure about that).

I have already used a tool called wget.exe to download the page in the past, but I'm still not entirely sure that it doesn't modify it before it writes it to disk.

Also what about the hex-editor itself? Does it modify the file (or the display of the file)?

So that (hopefully) gives you an overview of what I am looking for here.

Fiddler (Windows): http://www.fiddler2.com/

Here is a screenshot showing the HEX viewer:

_{(source: fiddler2.com)}