I make a lot of casseroles, soups and other dishes that call for cooked shredded chicken. Normally I poach boneless, skinless chicken breasts to achieve this, which doesn't necessarily take that much time.
Recently, though, I bought several packages of boneless, skinless chicken breasts marked down for 60%. Since the sell by date was that day, these needed to be frozen or cooked right away. I don't have a big extra freezer (or even a little extra freezer for that matter), so my space is limited. I forced them in the freezer for a couple days. Then I was looking at the schedule and the meal plan for the week and realized in order to fit everything in, we needed to eat out more than our usual once or have some things precooked.
I decided I could poach some chicken ahead of time and as I was standing at the freezer one night getting chicken out to thaw so I could poach it quickly in the morning, I realized there was a better way. So I pulled out my 6 quart slow cooker, placed 6 large boneless skinless chicken breasts in it and put it all in the fridge to thaw. The next day when I got home from work (I only work until 1:00pm), I set the slow cooker on low.
The interesting thing about defrosting the chicken directly in the slow cooker crock is that there was lots of juice in the bottom and I didn't have to add any extra water. If you defrost your chicken separately, I'd suggest adding about half a cup of water per 4 chicken breasts.
Once the chicken was cooked through, I took two large serving forks and pulled them against each other in the chicken to shred. This was much faster than using two regular forks. After cooling for a while, the chicken was divided into 2 cup servings, placed in freezer bags and returned to the freezer until needed. They should last me a few weeks and it's one less step to get supper on the table on busy evenings.
(If you have a KitchenAid mixer, I've also heard you can use your paddle attachment to easily shred cooked chicken in your mixer. I do not have a KitchenAid, so I haven't tried this.)
UPDATE: In preparing for the power to be out during Hurricane Sandy, I cooked 9 pounds of chicken breasts in the slow cooker and shredded it. I found that by putting the cooked chicken breasts in a 9x13 casserole dish, I could use two forks to shred it and pull the shredded chicken toward me. Working in batches of roughly 3 pounds at a time, I was able to fully process the 9 pounds of cooked chicken in about 15 minutes. It made almost, but not quite, 18 cups that I packaged up in two cup portions.
Find the whole "Working Ahead" series here.