That's cool. I assume you're using a picture control?

Yes. But I had to use the Mouse VIs and user events instead of the Mouse Move events because I need to detect when the user moves outside the bounds of the VI in order to know if they release the mouse button while not over the VI. I've talked with various developers about ways to resolve this ... it's a hard problem given the Windows API we have to work with. In my app, I can tolerate the polling loop that is necessary. Most apps wouldn't be amenable to that, so we can't do it for LV generally.