On January 1, 2010 these IRCs won't be worth. So they have to change for stamps before that date.
In some places are selling the new IRCs and their end date is in dec 2013.

I have voted!!
Kellan is the best!!!

New Moon, 2012, Avatar.

-Robert Pattinson
-Kellan Lutz
-Kristen Stewart
I think i will writte to the rest of the cast soon.

I use IRCs, but if you can buy UK stamps, it's better and cheaper.

I also think it's better during the season.

Kristen Stewart

Well, I sometimes think so, but really I think it's not so important. Depend of the celebrity. If she or he is a little silly maybe doesn't like the photo and doesn't sing it. But in general, I think that doesn't happen, with normal photos.

ekkusu wrote: 2. I live in Hong Kong, China and I want to send a letter to the UK. How many IRCs should I put into the envelope? 3?

I think 3 will be enough.

I had to go to the main por office in the city where i live, because in the others there weren't IRCs.