While it seems PC gamers may be able to bypass the censorship of Left 4 Dead 2, Xbox 360 gamers have no such luck. But what about importing?
There's a few options here. You could import from New Zealand or the UK, as the PAL version released in both countries escaped the censor's knife.
But you could also import the region-free Asia version from Play Asia. It's uncensored, will work on your PAL console has an English language option, and best of all, is only $US50. That's considerably cheaper than you're going to find in NZ or the UK.
Note: neither the US nor the Japanese versions are region free.
Also note: Forgot to mention, you'll be importing a banned game. Customs may confiscate it, if discovered.
Where are you getting your Left 4 Dead 2 hit from?
Buy Left 4 Dead 2 [Play Asia, thanks Paul!]