Yes, I have done this a couple times. I'm currently 20 hours into a 24 hour fast from food but I'm not alone and obviously still using technology. I plan to do this full challenge sometime between Christmas and New Years. There has been tons of research on fasting and there is nothing unhealthy about doing it for 24 hours. Some people take this to the extreme and do 30 day plus fasts. Some say fasting can cure any disease.
Here is a pretty good video on the subject: