DonorsChoose.org offers funding for selected school projects. Too much to describe here briefly. A teacher who just received notice of funding pointing me to this site.
What tools do your students need to increase their learning efficiency with Tablet and other mobile PCs? A cart? A projector? License for a software package for a budding astronaut or a struggling special ed student? Submit a proposal for it.
Also, check out the 30% off coupon when you shop at Gap and other participating stores. In exchange for your purchase, the store donates 5% of the sale to DonorsChoose.
The site directs teachers to a special page; use the link in the right hand column on the home page (I almost missed it twice when skimming the site during the first view.)