ASP.NET AJAX Extender for multicolumn drag & drop
Drag and Drop is very popular in AJAX websites. You can rearrange content on a website as you like and gives you some level of personalization. However, free form drag drop is a problem because the content gets messy as you drag things around on the page and there's no logical organization. So, a popular choice for drag & drop is to use column wise content flow where you can drag and drop content within column or across column. This ASP.NET AJAX Extender allows you to do that very easily.