Is there a wireless earbud that works with a standard headphone jack?
Most wireless earbuds are specifically designed to fit a brand of phone. That is why there isn't really a universal earbud. This is a money making market. As in, Nokia wants Nokia owner to only use stuff for Nokia. Why would they allow Motorolla to make money off of there idea? Best used with bluetooth. Really, you are looking for wireless headphones. I've personally never seen wireless headphones that hook up to a wireless device.
What your describing, it'll have to have a sepreate power pack... You can't trasmit with the power coming through the cord. I am sure you still have to get the phone out of your pocte to answer the phone, plus tangeled wires to go with it. Not sure you could market it blue tooth has it beat hands down. I would look for this at a truck stop if it exists it will be there.