At design time, you can use the Object Inspector to set the properties of the components of your forms and other designers. In Delphi 4, Borland introduced a run-time Debug Inspector, which has a similar interface and shows similar information. Before Borland added this feature, I implemented a run-time clone of the Object Inspector meant for debugging programs:
It allows read-write access to all the published properties of a component, and has two combo boxes that let you select a form and a component within the form. Some of the property types have custom property editors (lists and so on).
You can place the Object Debugger component on a program's main form (or you can create it dynamically in code): It will appear in its own window. There is room for improvement, but even in its current form this tool is handy and has numerous users.
This component's source code is freely available in the Tools folder of the book's source code.