Education is a broad category... geek-ish is equally broad depending on application.
Prime Directive... LOCAL...LOCAL...LOCAL. Your operative or key word is impact. You want to insure that as much as your dollar achieves its intended objective and that you have the ability to (if you choose) to verify the impact. Avoid a national or international blunderbuss -- such an approach scatters your money, creates too much dilution and generally includes excessive overhead.
Out-of-the-Box Brainstorm Suggestions:
Crisis Hotline, Woman's Center (or an similar support system for domestic abuse), Big Brothers Big Sisters, Homeless Shelters, Addiction and Rehabilitation Groups
You can also use Charity Navigator to assist you in researching specific organizations.
Each of these can be geeked-up to provide uplift and outreach were normal "geek enablement" or "geek opportunity" might otherwise simply be unavailable due to lack of funding. KEEP IN MIND -- Educational opportunities and technical services are very low priority when safety, food, and shelter are priority one!
Just a thought...