Jason writes –
Relive the glory (gory?) days of early computing with these two great sites for vintage computer kits. Briel Computers has kits for the Apple I (Replica I) and the Kim-1 (Micro Kim). And, Spare Time Gizmos has a has a kit for the Cosmac ELF (ELF 2k). These kits are great ways to learn the basics of computer architecture and data organization.