Yes. I am a HAM radio guy too... KC5HOK...
I have actually built a J-pole antenna and they do work well. They are not difficult to build either.
Since we are talking about FM.. the antenna would work best if it were "longer"...
The frequency range we want is lower; the antenna must be longer.
It might actually work just fine the way he shows it but an optimum setup would be to adjust the setup for the 80-107Mhz band as opposed to the 144-146Mhz band as our friend has done. These adjustments would require that we lengthen the two sections appropriately. The formula and alternate design can be found here
http://www.mycal.net/projects/mpr/jpole.htm Also, he has the "curly" loop up at the top. I believe this is what provides the 440Mhz functionality and that is certainly unneccesary for FM listening. Eliminating this would simplify the design and construction.
Hope this helps.
Oh. These antennas are omnidirectional.
If you want to get REAL serious about this go for a Yagi antenna that is HIGHLY directional. They require that you "point" them in the direction of the radio tower but provide the best performance.
A TV antenna on a tower with a rotor would be ideal.