I was talking to a colleague today about how I quickly capture notes on my iPhone and iPad. My goto app on the iPhone is Drafts (by Agile Tortoise). Drafts lets you get stuff out of your head and on to your device quickly. Once you've captured the information, you can decide what to do with it (e.g. send to Facebook, Twitter, save as a text file, Omnifocus, or a whole host of other possibilities).