I heartily second the recommendation for "The Idea Factory"! I'm currently reading this book and aside from the seriously impressive run of successes, the characters are really quite amusing at times too. E.g., Shannon built a desktop calculator that operated using Roman numerals only ("THROBAC") in order to amuse himself. And some of the whimsical creations were pretty impressive in their own right. E.g., his maze-solving mouse "Theseus" learned the maze layout on progressive runs through the maze by using relay-based logic.