This is more of a ditty than a feature, but it's fun and useful none-the-less. I've been adding and re-ordering Sueetie Marketplace contents recently and wanted an efficient method of ordering the display of categories. Nothing easier than drag-and-drop! Here's a screenshot of the Category Display Order widget on the Marketplace Category Admin page to give you the idea.
Once again jQuery comes to the rescue for an enhanced user experience. We're using functions straight out of jquery-ui-1.8.13.custom.js to handle the drag-n-drop and cool "Categories Updated!" slider to indicate the update.
For the behind-the-scenes category updates we're using a jQuery Post to an .ASHX handler. Nice.
We're not done with Marketplace yet--for both ditties and features, so hang around.