We like the overall look and feel of
#43,
#44, &
#45. One suggestion would be to have the envelope first, the wireless signals in the middle (and perhaps even play with them configured within the circle differently) and then the cell phone on the right, as if showing the message going to the phone.
We would also like to see
#45 reversed, without the black background. We like the green/black combination, just a little concerned with using the black background.