I've deliberately searched for a few terms that I knew would be banned ie. "Tiananmen Square," "Tibet," and a couple other items from a list of terms censored by the Chinese government. However, I've yet to 'accidentally' run into any censorship. If you use google.cn then supposedly it lets you know whenever a query is being censored. I've yet to have that happen. So, practically, no.
Interesting, we hear (as you know) censorship is rampant. Nice to have someone there to let us know the real story.. keep in touch.
On the other hand this message may get ya tossed in prison as a spy.