Overlaying features like in-line drag n drop and color adjustment to Panels module

One of the more enjoyable tasks I've had with Drupal in the last few months is figuring out a way to give the power of panels to our kid users without all the ... well, power. Our code is currently bundled as a custom (not quite releasable) module. I think some of the ideas that came out of the process might be valuable, so I'm sharing a little screencast demo. This custom module layers the following features onto the Panels module:

1. The ability to add, remove, and re-order blocks directly on a panels page. The Panels module requires you to use a powerful (but complex) edit page to do this.
2. The ability to restrict blocks to particular columns / regions. We needed to restrict the placement of blocks in order to keep the page layout clean. Our module adds a config page to select which blocks are available for each column in a 3-column layout.
3. The ability to save per-panel settings. Because we wanted each panels page to have different features like colors and background images, we needed a way to associate a panel pane (which is a block added to a panels page, for example) with particular settings. Our module includes a panel settings table to store these.
4. We also created a block that allows a use to change different colors on a page, or upload a background image.

I learned a lot of fun jQuery stuff building this module out, and finally ran into Internet Explorer's css file limit (my head is still a little bloody after that one).