OK, I tried this a couple times today, with disappointing results. I was trying to use it to help me focus on a video lecture I was watching, but I found it pretty hard to maintain any sustained increase in my level of activation... even when I got it to spike temporarily, it would immediately start going down. Also, the fact that it read data from my fingers meant I couldn't use that hand to create spaced repetition cards. Overall, it served as way more of a distraction than an asset, and I don't think I noticed any focus benefits immediately afterwards when I stopped using it and restarted the video I was watching from the beginning.
It's conceivable that you could make this work through a gradual increase rather than sudden spiking, or configure the dial so that it would only start to make noise once your level of activation went below some threshold. I might experiment with those ideas in the future.
If you want increased alertness, there are other hacks in the thread for that, like D_Malik's ideas of blue-tinted glasses or spraying/splashing water on your face (and of course there's always caffeine etc.) Supposedly yawning also improves alertness.
Hmm, okay. I was considering trying it on its own, rather than while doing something else. I know I wasn't able to do autogenics exercises while trying to do something else before, and now I sort of can after having practiced, so I would expect it to go poorly to try to go the other direction for the first time while otherwise occupied.
After you mentioned this I realized I have all the parts on hand to make a DIY galvanic skin response sensor. I got the hardware set up, and now I'm working on getting the software set up in a nice way. Hopefully it will work out :-)
Thus spake Eliezer:
It seems that many here might have outlandish ideas for ways of improving our lives. For instance, a recent post advocated installing really bright lights as a way to boost alertness and productivity. We should not adopt such hacks into our dogma until we're pretty sure they work; however, one way of knowing whether a crazy idea works is to try implementing it, and you may have more ideas than you're planning to implement.
So: please post all such lifehack ideas! Even if you haven't tried them, even if they seem unlikely to work. Post them separately, unless some other way would be more appropriate. If you've tried some idea and it hasn't worked, it would be useful to post that too.