"US law: all charitable contributions from businesses to be presented in form of giant novelty checks"?

False. That's only for photo ops. Most businesses that make charitable cash contributions (for example, to the United Way ) just cut a regular check, or do an electronic funds transfer. Other contributions take the form of 'in-kind' donations; for example, when Hurricane Katrina hit, AT&T distributed prepaid phone cards to the victims, other companies provided things like food, clothing and blankets.