Concise electronics for geeks (2010)
For those looking for a less-concise, but more comprehensive reference, The Art of Electronics was just released in its 3rd edition!http://artofelectronics.net/With a lot of relevant new content (references to Arduinos, etc), which is great since the last edition was from 1989.And while the basics of transistors, etc, haven't changed since then, it's arguable that the kinds of circuits that are of most relevance may have changed. (A/D conversion, general interfacing with digital logic, things that didn't have simple IC solutions in 89, etc).