Thanks for all the suggestions. (I blogged asking what the best intro book to investing is for a high school graduate.)
The overwhelming favorites were "Intelligent Investor" by Ben Graham, and "The Only Investment Guide You Will Ever Need" by Tobias. There was then a looong laundry list of other titles (check out the comments here to see the books mentioned), many of which I have never heard of. I picked up a few, including the previous 2 – it’s about time for a re-read!