In LabVIEW 8.0, you can make your VI front panels partially transparent while the VI is running. This can be handy when you have a "floating" front panel window that you want to be always available in your app, but perhaps you still want to have a global view of all the contents of your desktop. To play with this setting, check out VI Properties > Window Appearance > Customize... > Window Runs Transparent. You can also set the transparency level to a value between 0% and 100%.
For those without 8 (but with windows), this is achieved through windows API functions as demonstarted in the attached VI (which includes a VI from the winutil library). The connector pane and FP are not properly set up, but it shows the concept.