The necessity of notepads (or a pen and your hand)

Thoughts are tricky creatures to manage. Sometimes you spend ages rumaging around for one specific thought and just can't catch hold of it, only for it to pop out and taunt you when you least expect it.
At this point, the pen you should be carrying about comes in handy. Whether it's a to do, a question, a eureka moment that could change the world, it will be of no use if you can't pin it down with ink. It's almost like a race against time to find something to get it down with before it darts off again - though that could just be me, with my attention span of a gnat always dashing from one place to another before being squashed.

Unfortunately, I hardly ever have paper in that 3 minute window of opportunity (see? Really short attention span!). Even if I did, it would go in my bag and would soon be lost in the small forest in there. So, I have to use the one write-able surface that will stay attached to me hopefully - my hand. It tickles, and looks odd but it works. By glancing at my hand right now, from the few words on it, my brain suddenly snaps onto what I meant by that word on the whole. I know:
 - I need to revise moments. Really need to. REALLY badly!
 - Fehling's solution - why do we have to make it fresh in the lab?
 - I really need to be more careful with my ink pen (ink splodges everywhere!)
Even better, it's better than a cryptic code. Few people see my hand that closely. Even if they do my handwriting is bad enough already without smudging the ink or the lines of my palm that it is illegible. I myself can only make out rough letters but that is enough.

The obvious downside of that is that it is really quite short term. I have a few spontaneous writing ideas a week but I hardly ever get round to writing (Only once a year really). And I wash more frequently than that (I'd have hoped that was obvious though) and my hand is too small for that, despite my lanky fingers (all the more surface area for writing on). So I always have a small notepad that goes in my backpack, my handbag, my suitcase. Yes, the hazard of that is that people can look at it and laugh at all the appaling writing in there, but it works well for capturing free-roaming ideas. Not only that, but real life has some real novel worthy conversations! I hear some amusing comment ('I feel about as useful as a defibrillator in a funeral parlour!' and 'I sure hope insanity isn't contagious!) and rip out my notepad and franctically jot it down. Yes it looks odd to bystanders to see some deranged teen drop everything for no reason and write something in a battered notepad, but it works.

Where else can you keep ideas? The Sticky notes thing helps, but gets too cluttered, as do endless tabs of Wikipedia articles with interesting facts. That, or do you just keep ideas firmly in your head until required (how can you do that though?!)?