When it comes to iPhone note taking apps I am pretty sure I have at some point bought and tried a majority of apps that are in the App Store.  Over the years I finally whittled the list down to just a few core note taking apps that I really do use on a day to day bases.  Here is a quick rundown:
Squarespace Note
I don’t think I could have designed a better looking than Squarespace Note.  Launch the app and you are greeted with a blank white screen and a keyboard.  That’s it.  From there you type your note, and with an upward swipe of your finger your note is off to a predetermined destination of your choice.  You can choose between sending your note to Evernote (my current choice), Dropbox, Twitter, Facebook, Squarespace or an email address that you have preconfigured.  It’s dead simple and I love it.

Captio
Since I use Spootnik’s Omnifocus sync service I can email myself tasks and have them drop straight into my inbox.  However, there I times when I do not want to open up my email and have my inbox become full with new messages.  I simply just want to send an email out.   Captio let’s me do that.  Just simply choose a default email address that you want to send your email to and then you are set to go.   Then when you launch the app, you simply type your message and hit send.

iO6 iPhone Notes App
For times when I just simply want to jot down some quick info that I know I will quickly throw away, I stick with the stock Notes app.  I personally can’t stand the faux legal pad, however it does work seamlessly and with iCloud sync it’s a quick and easy way to get between my iPhone and my Mac.