From Information Week about her Etech talk:

"The "ubiquitous games," or "alternate reality games," are part of an overall change in how technology is being evaluated. In the next five years, the criteria used for evaluating personal technology will shift from things like cost and features. Instead, people will evaluate technology based on whether it improves their quality of life and happiness, she said. (...) Ubiquitous games are designed to be integrated with real life, and improve quality of life, McGonigal said. They're designed to "intervene against the widespread public alienation and lack of engagement in the complex world of everyday life.""

Some examples:

"Two years ago, in a game called the Ministry of Reshelving. McGonigal asked people to reshelve copies of 1984 in bookstores and libraries, removing it from the fiction section and putting it into the current affairs, military history, or some other section that was, she said, more appropriate. The call went out on the Web, and the activities were recorded on the Flickr photo-sharing service. (...) Tombstone Holdem Poker. A Web site instructs players how to read tombstones as if they were playing cards. The last year in the date of death is the card value -- for example, 1945 is a 5. The shape of the tombstone determines the suit: A pointy-topped tombstone is a spade, rounded is a heart, flat is a diamond, and cross is clubs. Surprisingly, this turned out to be popular among government agencies charged with maintaining historical cemeteries, which are often unused, and therefore in constant jeopardy of being shut down by cost-cutting governments"