Has anyone used the "Jupiter Jack" and does it work well?

I have used the Jupiter Jack phone adapter. Although the product does "work" its performance could be better. It uses the frequencies 99.3 and 101.3 FM on the radio. In a lot of places, people report interference from radio stations using those frequencies, so you should probably check if one of those frequencies is clear in your area. The other issue is that the signal given by the Jupiter Jack is very weak, so you will need to have it positioned close to your antenna. (Just putting it on my passenger seat was too far!)

If you look at the reviews on the Does the Product Work website, you will see that 72% of people say it does NOT work and 28% say it does work. (http://www.does-the-product-work.com/jupiter-jack/... Many of the people who rated it poorly complained about the static they were getting on the call. But those who rated it highly are enthusiastic about the Jupiter Jack and many say that after a little trial and error it worked great.

So, if those frequencies are clear, and you can place your phone close to your antenna, and you can spare the cost, it might be worth a gamble.