Google's robots.txt http://www.google.com/robots.txt disallows /search but not //search.

However, if you search site:http://www.google.com/search and show omitted search results, you get a bunch of results (all 404s).

If you do this there are some strange results on the last couple pages.

For example: Obama won't salute the flag | Phallectomy | horse+mating+video | feral+horses+induced+abortion | Lactating+dog+images | animal+mating+video | mating+mpg+-beastiality+-...

So, Half Life 3 confirmed.