And with the announcement of iOS 5, Apple has changed their App Store guidelines to ban such apps. Section 22.8 of the revised guidelines states that "Apps which contain DUI checkpoints that are not published by law enforcement agencies, or encourage and enable drunk driving, will be rejected".
Apple's ban follows RIM, who removed said apps from the App World months ago. There is no word on whether Google will comply with the measure. But given their lax restrictions, we doubt they will institute the ban unless there is more formal pressure.
Jalopnik points out that, as such apps rely on crowdsourcing, drunk drivers could indicate such DUI checkpoints by other, less explicit means. Regardless of whether you think that such apps really 'encourage' drunk driving, Apple and RIM are making the right move. If someone lost a loved one to a driver using such an app, the courts could deem Apple/Google/RIM liable.
source: Apple via Jalopnik