To get things started, check out this pink ribbon knitting chart. You can use this chart in a variety of ways, including working the design into a knitting project, adding it after the fact with duplicate stitch, or even using the basic outline to bead the design onto a piece of knitting, as you knit or afterward.
This would be a great, simple addition to a bag, scarf or even a sweater to wear when you want to show your support for people with breast cancer. And of course you could work it up in different colors to support different causes. (There's a great roundup of what different awareness ribbon colors represent at Fire Mountain Gems.)