Cnet report an idea which I have long been expecting, a device that checks the drivers breath for alcohol before allowing the engine to start. The alcoguard will be an option on its 2008 S80, V70 and XC70 models in Sweden, the U.S. and Europe.
As an option it is likely to appeal to the people who probably need it least, but I think legislation and compulsion will follow. I predict that at some point in the future, in regulated countries, cars will be fitted with devices that inhibit bad behaviour (including driving with too much fatigue or with low blood sugar levels) and report on illegal behaviour such as speeding and jumping red lights. However, I also suspect that there will be some countries who will always consider driving a right rather than a privilege.