I think about this a lot. For me, it's mostly smart phones that I think of. I can look at my phone to get the time, and as soon as I put it in my pocket I realize I still have no fucking clue what time it is. Sometimes I do this 2-3 times.
Also, I've realized how much smart phones allow you to not have to think for yourself. I've lost so much information because anytime I need to know it, I have Google at my fingertips.
These are just a couple examples but I'm curious what the rest of you think.