Any sewing skill level can contribute to some kind of sewing charity need and make a difference in a world the relies on us helping each other in times of need. Browse the various opportunities and find a charity project that matches your sewing skills and will give comfort to someone who is fighting cancer. If you have any doubt that a simple pillow can make a difference, be sure to read 10 Uses For Little Comfort Pillows by Pam Stephan, About.com Guide to Breast Cancer.
Connecting Threads offers a low cost pattern and directions to sew a comfort pillow for someone fighting breast cancer. (Note: This pattern was originally free but changed to a low cost pattern.)
ConKerr Cancer is a must visit. Their mission is "To make life brighter for children with life changing illnesses and injuries." Browse their site to learn how a "magic pillowcase" can make a difference.
sewing.org offers a great page of directions to sew chemotherapy turbans in various sizes for any size chemo patient.
Project Linus works to supply blankets, made by volunteer “blanketeers”, to any child who has been traumatized by medical or other causes. They have distributed over three million blankets to children in need since their inception in 1995... and no end is in sight.
This page sems to be for local groups but there is contact information so youmay want to consider this project for your sewing group.