That was great dude.Thanks for the response.
In fact i dug out some info on the moto website where i saw the accessories page.It had some headphones that are compatible for milestone and motorola claims that it can be used with ipod/iphone also.so we can assume 32 ohms for now.This is so because apple has mentioned the impedance of their headphones for ipod/iphone.
"Headphones acting as antenna" i agree with this to some extent, but iphone does not have FM radio feature.The reason for knowing the impedance helps because if i have a headphone with a greater value of impedance say 100 ohms, it would drain off the battery.I think so.
Anyway, thanks again dont mind my references for iphone if u hate apple products.
With greetings from India,
Kumar.