hard to say. I was listening to a radio segment on this, and someone brought up something I've always wondered about; signal strength vs the inverse square law. It turns out all our broadcast chatter fades out by the time you get to Pluto.
I think you can get around this using the 21cm band (hydrogen atoms), but it's hard to say; you're sending a signal out into a field of radiation.
That being said, there are so many galaxies, that intelligent life has to exist, regardless of how many conditions you sat against it.
Actually, the interest question for me is; why is so necessary that we be alone in the Universe? It would be such a waste of space...