the best way to handle a quick to-do? just do it! it often takes less time to finish it off while you have it in front of you than it does to write it down and come back to it later.
case in point? the random, unrecognized charge on my visa card. since the number was on the bill i just gave them a call and sure enough, it was something i charged. bonus of quick action: not having to spend days fretting about whether my card had been compromised.