This is a great book to pass on to a relation / friend who won't put up with dull science but you want to show how fun STR and so forth can be. Despite a few fuzzy areas, the general principles and the weird ideas are all there and the accessible way they are presented leads on to some interesting questions and conversations. But, don't think it is just for kids, someone reading over my shoulder on the tube started to ask me questions. The poor fool, he is now hooked.
Even if you are an accomplished professor of GR and all that, do remember to read it yourself first. It will let you know what questions you are likely to be asked & reminds you of the fun that it used to be when you first heard about these silly ideas!