nightcraw1er.488: I would strongly advise you not to use the wallet feature. A change of country, messed up IP or something along those lines will wipe it. Happened to me recently, am abroad a lot and multiple currencies is not possible (suprise) on the site.
It will all be spent on Christmas sale.
HunchBluntley: Pretty sure that's a "No".
If the person in question doesn't already have a GOG account, you could create a new account for them (ideally close to the date you intend to give it to them, so they can take advantage of the time-limited new-customer "welcome" deals), preload the wallet, then turn the account details over to them at the chosen time.
He already has a GOG account and many games.
This is sad. You can easily buy giftcard/vouchers for Steam, just like Amazon and other stores. It's something easy to implement and one of those things that if added no one will complain about (OK, maybe some people will still complain).
Guess I'll have to buy some games then.