How do Icelanders avoid dating relatives?

Most of the 320,000 citizens of Iceland are related to each other -- at least distantly -- and need a way to avoid becoming kissing cousins. So there is now a smartphone app that helps Icelanders avoid "accidental incest." Users bump phones. If they are related an alarm will sound. The app's slogan: "Bump the app before you bump in bed."

What is ricin?

Ricin, a poison sent in letters this week to President Obama and a Republican senator, is a natural, highly toxic compound that comes from castor beans. It can be fatal if inhaled, injected or ingested, causing respiratory or circulatory failure. There is no known antidote. The poisonous letters never reached the White House or Capitol but they put Washington on edge, coming as they did right after the Boston Marathon bombing.

What is the newest holiday in Colorado and Washington state?

Thousands of people are expected to travel to Colorado and Washington this weekend to take part in an unofficial counterculture holiday celebrating the legalization of marijuana. Some travel services are offering package tours to those interested in participating. More than 50,000 people are expected to smoke pot outdoors at Denver's Civic Center Park on Saturday. Thousands more are expected to take part in the first annual Cannabis Cup, an American adaptation of a yearly marijuana contest and celebration in Amsterdam.