This was...interesting. Not entirely what I expected, too.
The main character, Charlie Giles, has everything he wants from his career. His baby, an in-car stereo system/GPS/Bluetooth THING, is about to be released, earning his company bazillions of dollars. But then Charlie starts finding notes written in his own handwriting. Notes that he has no memory of writing. And when he gatecrashes an important meeting on the recommendation of a woman claiming to be a company employee, things go from bad to worse, and Charlie doesn't know who to trust.
The psychological element of the book was fascinating. I really liked the supporting characters, especially Charlie's brother, Joe. But I found Charlie not particularly likeable for some reason that I can't pinpoint.
Still, it was a fast-paced story that kept me guessing, and I enjoyed it even if it won't be making the list of books I'll reread at some stage!