It's a bit hard without knowing what you want...
Basically, you can drag any metafile (.wmf and .emf), .gif (also animated), .bmp, .png and .jpg (.jpeg) on your front panel. You can also edit control (Customize Control in edit menu), and insert any of there in a control. Best candidate for this is a boolean. For instance, valves are made like that.
If you need to draw things programatically, you can use a picture control. In this control (basically a blank canvas) you can draw lines, pictures (.bmp, .jpg, .png or raw 2d arrays), circles, text, boxes, etc. This is typically much harder, but you can make almost anything with this. With the use of events, you can make items move with mouse drags. The sky is the limit, if you have enough time. Look at NI's graphs in Controls>Graph>Controls. The Plot Indicators over there are actually picture controls where all the lines and data is drawn into.
Regards,
Wiebe.
