I recently just learned how to use the same block to make at minimum 4 different quilts and if you add all four of those locks as a sampler you then have 5 different quilts. It is called the 5 minute block which you can view the video here at
http://www.youtube.com/watch?v=TIxl3af3lzY.
I learned another techique using only two fabrics (one above uses 3 fabrics). In this one you just cut ANY sized square and lay one on top of the other with front touching each other and sew 1/4 inch all around the square. Then take your rotary cutter and ruler and cut diagonally once and than do it again on the other. It now gives you four sticthed pieces. When you open them up you can create a spinning wheel block and if you place one of the fabrics all same theme as center it creates another block.
Anyway both of these techniques will work up charity quilts fast. The first one with 3 fabrics gives you at least 4-5 different quilts to make.