Can I ship an iPhone to the Philippines?

I'd like to send my iPhone 4 to a friend in PI. Is an AT&T phone. She says that she will jailbreak it to work.

What problems do I expect to encounter? I've heard that Americans can't ship electronics to some countries. Will I have to pay any export tax or anything like that?

Yes you can ship to your country. Try buying from EBAY as this is one of best international shopping website
I would suggest you to buy Factory Unlocked version, because it will not have any contract with it, so can be used with any sim worldwide.
jailbreaking is easy process, but i think that jailbreaking of iOS6 is not available till now, but it will come within few weaks.

I doubt you have to pay anything extra. But this one time I bought a psp on ebay from someone in virginia and got it fedexed to me in the philippines, I had to pay like *** $60 import tax when it arrived.

btw, make sure the os isn't updated to the latest ios because i heard they can't unlock it if it's ios 4.something. Only up to the early ios 4. If it can't be unlocked, it will just be a very expensive (and thicker) ipod, just like my friend's lol and when she finally did try to get it unlocked, it was already on jailbreak and the guy tried to factory reset it, it just froze.