Once they were big enough and social and healthy, we returned them to the shelter, where they were quickly adopted. The experience was so fun and rewarding that we have gone on to foster two more sets of kittens, and plan to continue to foster. We jokingly refer to it as the Kitten of the Month Club. Our cats, ages 11, 10, and 6, are even getting pretty good about having kittens around.
Being foster parents has given us the opportunity to make a difference in the lives of many animals instead of just a few. If you have the resources to do so, we highly recommend fostering with your local rescue groups. It has its ups and downs but overall is extremely rewarding. :)