I simply can't believe that this book is out of print. It's one of the best, most thrilling, page-turning, paranoia-inducing, intelligently written, sarcastic, witty and just brilliant books I have ever read. I've read it three times already and when I get it back from my sister (don't ever lend books to my sister - you'll never get them back) I'll read it again. Thank god for Amazon Market Places - at least I know when I don't get it back I can get it here for 1p.
Trust me - you will not regret reading this book. It's far, far superior to the film (which, quite frankly, was crapperooney). The book goes into great detail, describing all the little things you imagine you might notice if you were to become invisible. I loved the bit where he describes his secretary coming into his apartment, looking through his drawers, using the toilet etc., and him just watching away invisibly in the corner, holding his breath. Also, the bit where he gets frisky with the woman at the party in a dark room. Suddenly, someone comes in and turns the light on ... just imagine what you'd think walking into a scene like that.
Get this book. You won't regret it. Now, if only H.F. Saint would write another book (or at least let us know what his supposed real writer's name is).