I often have days of no technology, and sometimes it's an entire weeked or 3 days of no technology (except for lights).
Regular breaks from the computer world to deal with the real world is something that everyone should do. Whether it means going camping, hunting, fishing or just being outdoors - those breaks from computers are a huge energy recharger!
As for devoting an entire day - people should be doing this regularly anyway - if they're not, they're missing out on life.
One thing that I require (yes, I said REQUIRE), is that when I go out to dinner etc, or even having dinner at home, phones are not allowed at the table - whoever it is can wait. There's no need to check a facebook status, or upload a picture of your food to facebook at that exact moment. Feel like sharing, not a problem, take a picture, then upload it later - believe me, the world can wait the 45 minutes!