Source Code & Description
RadComboBox provides support for multiple columns. Developers can now define any table structure and it will be applied to all combobox items. The key benefit here is that this is achieved using templates. Table structures can be easily customized and modified on the go, without the need to recompile / code anything.
Multi-column mode supports all advanced AJAX features of the combo � load on demand, auto-complete, etc. Items loaded on demand are automatically formatted using the ItemTemplate as well.