(or How NOT to be The Grinch)
In this podcast, we talk about two options to deal with your excess supplies of insulin that is still good to use, so that it doesn't get wasted.
1) iPump.org: This is a nonprofit whose mission is to provide critical, temporary financial assistance and free supplies to diabetics in need of all ages throughout the United States. They accomplish this through donations from those of use who may have spare supplies sitting around.
(In the interest of full disclosure, I am a member of the board of iPump.org since May 2008.)
2) Insulin For Life: they collect excess unused insulin vials that can still be used and distribute them throughout developing countries in coordination with local centers and International Diabetes Federation's "Life For a Child" program.
This page lists their collection centers where you can mail your insulin. Also, for members living outside the US, this another place you can send your excess supplies (specially strips).