Counting Australia with computers
Australia will be conducting a census in 2006 with an online option:
"In August, [the Australian Bureau of Statistics] conducted a test of the 2006 form among 6000 households in Brisbane, focusing on design and usability. Nauenburg said the trial was a success, with 4.5 per cent of households choosing to complete the electronic form. 'We learnt we have to continue to focus on accessibility and usability but it was good to hear that people would be prepared to conduct the census electronically,' he said."
Also in the article: the Swiss Federal Statistical Office ran their first electronic census in 2000 and only saw a 10% failure rate. (10% of questionnaires started online were not completed.)
The U.S. and Britain are projecting their first online censuses in 2010.
U.S. Census Bureau Usability Lab - an interesting site that appears to be under development.