There is an interesting post at Google System which talks about Google redirection feature which was exploited in the past. The Google search results have a very long URL starting with http://www.google.com/url?q=. While Google used this information to improve search results, it was used by many people to create site URLs which began with this extension.
These site ended up being percieved as Google owned sites and eluded phising filters too. Finally, Google took note of the matter and now it displays a warning. The warning message reads:
"The previous page is sending you to [new address].
If you do not want to visit that page, you can return to the previous page."