I don't know of any, but what about applying in the name of the school rather than the PTO? There are tax implications for grants given to organizations that aren't tax-exempt (501c3), so many businesses and most foundations won't do it. You can apply to Lowe's Toolbox for Education through your school if your PTO isn't 501c3.
- Craig
Links in this post:
Lowe's Toolbox for Education: http://www.toolboxforeducation.com/