Using Foreground Image

You can draw directly to the phone screen.
It is useful for a notification from a background program.
You need to install fgimage.pyd from here.

import fgimage, e32

img = Image.new((100, 16))  # create a notification text
img.text((0, 14), u'Hello world', 0)

fg = fgimage.FGImage()
x, y = 0, 40           # position to draw
fg.set(x, y, img._bitmapapi())  # send it

e32.ao_sleep(1)
fg.unset()                # then clear it


See (a bit) more discussion here.