Try contacting HSBC, Citibank, etc. in Hong Kong.
Citi in particular has a very good system set up for transfers between Citi accounts in multiple countries. This can be fee free, though that may depend on the specific account package, and it is relatively fast (a few business days). Then there is the problem of passing a local credit check, etc. It is probably a great deal of hassle. Also, do you want to call HK when the card is lost/stolen, used fraudulently, etc.?
If it is only for 6 months, it might be easier just to issue your son with the a credit card that charges the lowest possible foreign exchange fee billed in US$ (probably one issued by MBNA). If linked to a card in your name, you could even earn points or cashback on the charges, partially offsetting the currency exchange fees. Even assuming a 2% exchange surcharge (1% Visa/MC + 1% issuing bank), it would take approximately $5,000 in charges to equal the cost of 2 international wire transfers, based on estimated $25 each outbound and inbound fees on each such transfer.
Based on my understanding, credit cards, ATM cards and wire transfers all generally use the same interbank exchange rate as a base. The eact timing of the calculation and any surcharges applied by the transacting bank may affect the results, but in general these are the best rates an individual retail customer can get by any means. I generally find that the rates I get on my credit cards when outside the issuing country are very good even after accounting for fees--definitely far better than cash.
[This message has been edited by chalf (edited Mar 19, 2004).]