Singapore Airlines now offers wi-fi on its A340-500s, and will be adding the service to its 777-300ERs and A380s in the coming months.
Through November 30th, it’s $25 for 30 megabytes, which should get you through a flight, assuming you’re not downloading massive numbers of videos illegally.
I pooh-poohed getting wi-fi during long-distance flights, but I used it on a flight back from Frankfurt recently and I thought it was a life changer. I HATE the feeling when I land that there are a zillion work emails piled up waiting for me — I was able to get through them during the flight (and still work in a nap). That felt like it was worth $25 to me.