depends where to but i doubt it im afraid.
1. diff currencies may be a problem
2. the us, canadian and uk (plus all the others) itunes stores are all different (ie. diff music)
craigp is right. I'm in Canada and I've tried purchasing a gift card for friends in different countries. I also received an iTunes certificate from someone in the States, and it didn't work.
I sent an email to Apple to complain about this, and they said they doubt this policy will ever change.