I've got an odd request for a Java app.

Someone wants a scrolling banner for their desktop.  They want to leave
their wallpaper in place, but they want a Java app that periodically
scrolls certain text across their desktop.

So what SWT control would I use to scroll the text ?  How would I
smoothly make text scroll ?

And is there a way to make containers transparent ?  How about making a
shell totally transparent ?  Or is there a way to use a canvas as the main
container and not use a shell ?

Thanks in advance.  I hope these aren't silly questions.  I am pretty new
to Java and SWT.