Here's a fun article on RocketNews24 about the groundbreaking work NTT DoCoMo is doing in laboratory simulations of the potential for disaster at the Shibuya scramble caused by NTT DoCoMo's products. Or those of any smartphone provider, to be fair. Mathematical chaos. These kinds of things really tickle me. It must have been pretty fun for the DoCoMo researchers, too.
We do spend a lot of time eyeballing our phones here. Not just Japanese people, but ex-pats like me as well. I don't do this while walking, though. If I'm using maps on my iPhone for navigation, I find an out-of-the-way place along the sidewalk to stop and orient myself. If I receive a message, I usually wait until I'm sitting down somewhere to check it. But I have, on rare occasions, walked and phone-gaped, too. I'm not proud of it.
Never at the Shibuya scramble, though.