I did, after trying many more elaborated options. I liked better the simplicity of a simple .txt over any app. You can do everything just with the keyboard. To mark a to-do as completed I would just move it to the bottom.
So, I ask and say all this because when I started learning Rails almost 2 years ago, I decided to make my ideal to-do list web app as an exercise (yes, very original), with the idea that it would behave just like a text file, but with specific capabilities and nice typography. Truth is I been using it ever since, and now I wonder if I should polish it and release it publicly. Would you like to check it out?