We have a partial winner. My colleague Greg Elin has tracked down, on Recovery.gov, this announcement:

Obligated ~$47 million for EBSP equipment and ~$3 million for PSP equipment

That seems to correspond to this announcement from the 100 Days report:

2. Advanced Technology: Reveal Imaging Technologies of Massachusetts recently received a $47.5 million contract to develop, build, and install 123 reduced-size explosive-detection system units and their ancillary equipment at approximately 50 airports across the country, as part of the Electronic Baggage Screening Program.

That’s the closest we’ve gotten to finding a reference to any of the spending listed in 100 Days, 100 Projects on Recovery.gov.

Reveal Imaging has this release about the contract on their site:

U.S. Department of Homeland Security (DHS) Secretary Janet Napolitano announced today initial awards of $50 million in American Recovery and Reinvestment Act (ARRA) funds for explosive detection systems and advanced technology X-ray units that will streamline baggage screening and enhance security capabilities at airports nationwide. … DHS will purchase 123 reduced-size explosives detection systems from Reveal Imaging Technologies for approximately $47 million under an existing competitively awarded contract.