Toshiba P305-S8904 FM antanna

Ive got a laptop. Been a great computer for me but it has one feature I am unable to use. It has a built in FM tuner - something I would like to utilize. The software is easy but I lack the antenna to receive a signal. There is a Jack to plug in a antenna. Problem is: The jack seems to be a unique (propitiatory??) size. it is larger than a 3.5mm headphone jack. Anyone have any ideas of what size plug this may be??

Any one?

http://www.impactcomputers.com/v000932910.html
from Toshiba Forum here:
http://forums.toshiba.com/t5/Satellite-A-Series-Laptops/Fm-Tuner-Antenna/td-p/40231