Search engine censorship

Google recently launched a censored service in China[1].

Question: What other censorship occurs, and how do we know? Question: Will the Google research lab in China be working on censorship technology?

Bill Thompson wrote an interesting piece[2] on this topic:

[Jonathan Zittrain and Benjamin Edelman] have discovered over one hundred sites which can be found by searchers in the US but not by those in Germany or France.

He concluded that there was no public awareness of this censorship and no due process.