I did 2 of these a while ago for my mother in law and did the other one today, they are so nice to do and give the 'wow factor' to cards.
They are easy to do but you have to remember to cover the other side where you've stuck it on, but thats fairly easy to. Just cover with a matching peice of card on the inside, no one will know!
I find the best thing to use for sticking card and acetate together is silicon glue.