Version: 1.1.1 (using KDE KDE 3.1.2) Installed from: Unspecified Linux OS: Linux Sometimes to make diagrams more expressive it is useful to place different graphics icons on diagrams. For example, I actively use the actor icon on activity diagrams to denote actions made by user, and the computer icon to denote actions made by the program. I think the simpliest way is the possibility to paste raw images from clipboard. In more advanced way it is possible to arrange them on a toolbar.
The point of the UML standard is to standardize the graphic elements which are permissible on diagrams. I'm afraid this wish is out of scope for Umbrello.