I have a terminal command called "log" which takes a string as an argument. It basically takes this string and writes it into my log file, prepended by the current date and time. This log file is in my dropbox folder. Typing "log" with no arguments will open up the log file in my editor.
I have this set up with an Alfred workflow which works exactly the same way. I find it very useful for keeping track of what I am working on, what problems I was meant to be tackling, quick calculations I would like to keep a record of, etc
EDIT: reading the article more thoroughly, my solution is basically identical.
I do the same using jrnl (http://maebert.github.io/jrnl), which lets you do things like star, tag, and view entries from specific days - while still keeping everything in a plain text file.
This is a pretty neat hack! Unfortunately it won't work with my setup of NVAlt [0] (OS X) and Simplenote [1] (iOS). I've got NVAlt hotkey'd so I can bring it up anywhere and use it as a scratch pad all the time that I know will be synced to my phone immediately, the problem being it doesn't use iCloud but rather simplenote's syncing solution, I'd wager to bet that I could do something similar that edits NVAlt's local storage and see if it's auto-synced as well (I bet it is).
Your link to Ajour at the end of the article is broken. Link should be to: https://github.com/gopatrik/ajour as your link to to your main github page and is missing the "http://" and so it's getting appended on the end of your post URL.
A couple notes for anyone trying it: 'Notes' has to be running & there has to be an existing note with the first line 'Terminal Note'. Both could be handled if anyone wanted to make it more robust.
This will be great for shooting specific tidbits of info from my work computer to my iPhone (which aren't connected via iCloud).
iCloud Drive or CloudKit-esque storage would be nice, but the regular Notes app uses IMAP for storage, for what I imagine are "legacy reasons". (The Notes feature was originally built in to Mail.app and used IMAP notes. Yes, IMAP has a notes feature).