It's easy to block HTML referrers in Firefox: visit about:config and set network.http.sendRefererHeader to zero.
It's easy to block referrers in Opera: Make sure "Send Referrer Information" is unchecked at Opera | Settings | Quick Preferences
So how about Chrome? The man page is incomplete, not saying how to do this.
Googling sent me to a a Chrome extension. I have no reason to trust the author of that extension, so I looked a little more.
The answer is, surprise, in the Chrome help forum, http://www.google.com/support/forum/p/Chrome/thread?tid=63a866565ba8664f&hl=en
The thing is, I don't usually start Chrome from the command line, and I don't recommend doing so. If Chrome (or Firefox, or Evince, etc.) are given a command shell, they dump gobs of junk to, probably, stderr. So it's necessary to change the shortcut from which Chrome starts. Gnome instructions follow; Windows instructions, untested, are here. [ Note added 2012-09-10: I think the following is incorrect and that Firefox does require an extension to block referers. Bad Firefox, bad. Original text: I do not endorse their method of blocking referrers in Firefox, as it is simply not necessary to install an extension to do this. ]
In System | Preferences | Main Menu | Internet (your system may vary) right-click on Google Chrome. Add --no-referrers to the end of the command line. Kill Chrome. Restart Chrome through the updated shortcut.
On referrers: this is from a time when the Internet was a less dangerous place. I have trouble seeing how this was ever a good idea, but now it is simply an invasion of privacy. It isn't likely that any subsequent version of HTML will drop this, but it would be nice if browsers would default to not sending referrer information.
A note on the misspelling 'referer': the word was misspelled in RFC 1945 (!996 Berners-Lee, Fielding, Frystyk), which is a bit odd since they spelled 'referred' correctly. Wikipedia says the misspelling originated in a different document, by a different author. Fielding says that neither 'referer' nor 'referrer' were in the UNIX spell program at the time. I thought by 1990 everyone was using ispell or aspell; okay I never actually thought that. Paper dictionaries weren't available at the time? I'm just happy to not have my name as prominently associated with a dumb little mistake like this. Of course, it is just a dumb little mistake.