Skitch is an app made by the creators of Evernote that I think is just one of those rare game changers. In the most simplest, non-techie terms, it allows you to use pictures as notes which you can then sync with your Evernote app. I don't use Evernote. I personally find it too complicated though a lot of my friends love it, but I've found I can use Skitch in other ways.
I always take pictures with my iPhone; a pair of shoes I like, some earings in a magazine, a beauty product I want to research later or just something that inspires me. I usually store those pictures in my phone to review later, but if I don't get to them right away I forget what I took the picture for. Skitch allows you to doodle directly onto the photo with a small assortment of tools so you can document your purpose for taking the picture. So now, if I'm walking past say, a department store window and a mannequin has a piece of jewelry I like, even though I'm forced to take a picture of the whole mannequin, I can now draw an arrow, circle, scrawl or whatever to highlight the jewelry. Pretty cool.
I know what your thinking. You could do this with a bunch of kiddie apps too. But those won't sync to Evernote (if you're a user) and besides, do you really want a pre-school app on your phone?
You can find it in the App store for iPhone and the iPad and download it for Windows.