Anyone know of a super quick delivery service? I want to send a card to someone in China but I'd like it to arrive by Thursday (ideally) or by Friday at latest.

I couldn't find anything on a Google search.

It's probably impossible but thought I'd ask here for some ideas... cost isn't an issue.

Check out Same day messenger to see what they offer. Since they move parcels and fly cargo almost daily, they probably have a service for the letter mail variety.