Are there any "official" (meaning trustworthy) builds of Chromium for Windows? I am not interested in Google Chrome, which has branding/spying modules.
Not quite what you wanted: If you can't find Chromium, there's an unofficial build/fork called Iron. (Source code's at the bottom of the download page.)
Iron strips out the branding/spying modules and has a "portable apps" install which means you can install it even if the normal Chrome Installer can't reach the internet.