My post on Autism Rates in the US can be found here: http://www.stellamarie.com/index.php/2010/06/24/autism-rates-per-state

I consolidated for the other countries here:
UK 1/60
Canada 1/51
Australia 1/50
China 1.1 mil
Phillipines 500k
Thailand 180k

I decided to look up the rates worldwide just to compare with the US.

The UK is 1/60 according to the Mail in March 2009. The article can be found here http://www.dailymail.co.uk/news/article-1163606/One-child-60-suffers-form-autism.html

Canada has slightly higher rates.  According to the CBC http://www.cbc.ca/news/health/story/2009/04/02/f-autism.html 190,000 children in Canada have autism, and that makes the rate about 1/51. I took the amount of children in Canada 2006 from this website http://www40.statcan.ca/l01/cst01/famil50a-eng.htm

Australia is 1/50 according to an autism advocacy in Australia.  The article can be found here http://a4.org.au/a4/node/225

I'm not sure about the accuracy of this website. http://facts.randomhistory.com/2009/09/21_autism.html
But they list:
"The WHO estimates that there are 1,100,000 cases of autism in China; 650,000 in the UK; 500,000 in the Philippines; and 180,000 in Thailand."