The only problems with those dinky FM transmitters are the power output (you really don't get much more than 200 feet or so with any kind of useable signal) and frequency stability...actual purpose-built transmitters work much better.
This one doesn't relate to Wal-Marts, but it's something I've still been known to do //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
I've modified the radios in my van to transmit on any frequency whether it's in the amateur radio band or not - so I can transmit on commercial frequencies. One day when I was bored, I decided to look up some channels for fast food places - because when you order, there's a frequency going back to them and the channel that they're talking to you on. Once you know the channel, all you need to do is park within line of sight to the restaurant, and have a little fun //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
If you're on the input side, you can order people's food for them...funny, I never remembered ordering 8 Big Macs, 10 chilis and 5 sides of fries...//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Or if you're on the output channel, you can pretend to just have learned English yesterday (not a stretch from reality for some folks) or play around with them however you want //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif This one can be absolutely hilarious because you're listening to their reactions on the other side of the conversation //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
I have too much free time.