This is an incomplete selection of search results which Google.cn self-censors working together with the Chinese government. Google does not censor access to the site itself, it only censors the site within the search result; access to the sites is blocked by the Chinese government.
Note: Even though it seems as though the right-most radio button ("search Chinese websites") was selected for some searches, this selection was not chosen by me and is automatically enforced by Google for certain searches – Google.cn doesn't allow you to search for e.g. falun gong using the "All websites" option. Whereever possible, the "All websites" selection was chosen.
Also note that while Google below the results sometimes points out that results are missing – the note can be roughly translated as "According to local laws and policies some search results are not showing" – it doesn't always, e.g. when searching for playboy.com (this behavior resembles Google.de's self-censorship when searching for e.g. stormfront.org, or Google.fr's censorship of ety.com).
To reproduce some of these searches, switch your browser language to Chinese and go to Google.cn. Some search queries, by the way, are case-sensitive.
(Screenshots from 1/26/06, updated 1/27/06 on, by Philipp Lenssen.)