I have a US$10 itunes card (from a beta test) which I don't really need. I like to exchange it for paypal credit (same amount pls) since I have some stuff I am eyeing but was too stingy to pay out of pocket. Not sure if this is against the rules? I am posting this in the lounge if it helps.
There's a social group called "Promo Code Exchange Group" which is specially for this type of trade. The tricky thing with trading for PayPal credit is that some fees apply, so it would cost more than $10 to give you $10. I'm in the same position as you (US$10 card) and I find it easier to swap for promo-code(s).
Ah, I didn't mean same amount as in I have to receive exactly $10 but that the other party transfer $10 to me. Cos sometimes for this sort of trade, there are people who offer less than the amount the card is worth.