Sometimes the best technology is the simplest. Here's Matt Cleaver's take:
"….there are times when you just have to capture an idea
on-the-spot, and the most convenient way to do it at that particular
time is by writing it down. To do this, you are supposed to use your
“Ubiquitous Capture Device,” something you always have with you so you
can never miss recording a thought. I’ve tried different ways of doing
this, from carrying around note cards to scrap paper to moleskin
notebooks. None of my solutions thus far has been satisfactory…."