Be advised This post is quite old (03 Apr 2013) and any code may be out of date. Proceed with caution.
Update Feb 2017 I’ve happily used this TODO app for the past ~4 years, but I’m taking it down with the rest of my old PHP hosting. In conjunction, I’ve removed the demo-related content from this post. For anyone interested, I’m now using Wunderlist
I've been looking for something similar for awhile. Looked at Evernote and other apps, but nothing was as simple and lightweight as this app. Only problem was that the items stored in the app didn't persist, as there was not database/storage behind the app. So I went ahead and wrote my own.
The bad news - this isn't a secure application, SQL injection attacks will succeed here. Also, some of the icons don't seem to work outside of Chrome.
The app also works on mobile phones, which is great.
If you want to set up your own instance of this app, you can download the code from GitHub. Obviously you'll need your own hosting and a MySQL database, but the rest should be pretty easy to figure out.
This isn't a fully finished product by any means, but I wanted to put it out there in case there's someone like me who needs a simple to-do list app.