NCTM offers a wide variety of grants under its MET program. The deadline for the first round is November 7. Another round will happen in the Spring for a different set of grants.
From the MET Grant website:
The Mathematics Education Trust:
Supporting Teachers ... Reaching Students ... Building Futures
Mission: The Mathematics Education Trust (MET) channels the generosity of contributors through the creation and funding of grants, awards, honors, and other projects that support the improvement of mathematics teaching and learning.
For more information visit:
http://www.nctm.org/resources/content.aspx?id=198