That's a good question... I don't have an immediate answer but the New York Times ran an interesting article today about how technology leads to more distraction:

http://www.nytimes.com/2010/06/07/technology/07brain.html?emc=eta1

Very interesting article, and it actually partly answered my question. Thank you Jon.

If the current "mental price" is way too high, or the potential price in the future is unpredictable, I don't know if we should to encourage our kids to play online games to learn foreign languages.

At least, "playing every day" is very risky. :-(

There was a nice counterpoint to the NYT article in the Wall Street Journal:

http://online.wsj.com/article/SB1000142405274870402530457528497347269433...

"We are now witnessing the rapid stress of older institutions accompanied by the slow and fitful development of cultural alternatives. Just as required education was a response to print, using the Internet well will require new cultural institutions as well, not just new technologies."

In the article Clay Shirky argues that technology itself does not lead to distraction. Issues arise when teachers and parents do not engage in the work of sifting through the multitude of options to find the truly useful stuff and then set up well-planned parameters within which these new technologies can be employed.

Wow...Thank you Brad for bringing the opposite opinion and its source.

May I say---In addition to teaching the kids how to use new technologies/methods, the teachers also should teach them the new Internet culture?

I don't begrudge children the opportunity to learn with internet games or smartphone apps, but I do see some problems that come with the new learning opportunity--students can get easily distracted by what are available online/on the device while studying. That being said, it is beneficial for adult language learners to use smartphone apps or other high-tech resources for studying with their busy schedules. The Mandarin Center actually has a list of those apps, you can find them at

http://themandarincenter.org/rating_browse_tags/241

The Mandarin Center's resource link provided by ameliawang is very useful. Thank you Amelia.

No, not really..