[tardo99]

You definitely can broadcast packets via wifi. I mean, that's essentially what you're doing when talking to an AP. All the other wifi antennas/chips in the area can see the data you're sending. You'd have to do some hacking on the receive side to get the data out, but that should be pretty straightforward.

[labawi]

To receive, just set your interface to monitor mode, set the right channel, dump and filter. tcpdump works fine, though you probably want to read and process the data with a custom application.