More T-shirt diapers!!!
I also got a free Seahawks T-shirt at one of the home games last Winter, but they only had large sizes.
So... How about a reversible 2-T-shirt fitted diaper? Great for older heavy-wetting babies or overnights. :)
 I used my M/L fitted template for this. I cut off the sleeves to begin with.
I traced it on the first T-shirt, and used scissors to cut out just one layer.
 View with the shirt opened up.
Really, the T-shirt is just like cotton jersey fabric yardage. 
 Then, I used my rotary cutter to cut out all the other layers.
 2 layers of one shirt, and 2 layers of the other.
 Faces inward, and from here you just follow my basic diaper tutorial for the shell.
 Next, just cut up the remaining yardage into your soaker/insert.
I decided to use my non-serged insert/soaker method.  It seemed the most practical.
I had enough fabric for a 7-8 layer soaker/insert out of each shirt.
 Everything all ready to stitch up.
All sewn up! A walking foot is your best friend with jersey fabrics.