Er, not sure what the "Yes" is in reply to. I only asked one yes/no question, and its answer would appear to be No. :) Unless your "funny" site is a page-by-page parody of your real site, which seems a bit far-fetched.
Take a moment to read the post about using "example.com". It will save the moderators a bit of aggravation; they've got enough to do, weeding out the spam posts that tend to show up around this hour of the night.
Oh, and when I said
I meant: The "HTTP_HOST" condition looks at your own domain name. Any other value in this slot-- such as the other guy's IP address-- will always fail. If you want to test against his IP, use the "REMOTE_ADDR" condition.
Your original RewriteRule is syntactically correct, it's just using the wrong values in the wrong places ;)