Jim Minatel provides a great update on the Amazon Upgrade program that I previewed in this post last summer. His post talks about one of our WROX books that is already in the program. I agree with Jim that Upgrade truly helps solve the instant gratification disadvantage Amazon faces with your local brick-and-mortar store. What's even better is the very low price you're likely to see on e-book access through this program. Yes, you have to buy the print book too, but for portability, easy online mark-up, anywhere access, etc., it seems like a pretty small price to pay.
One last point, and this is where Amazon always makes me smile: Being the data junkies they always have been, Amazon has kept a record of all your print book purchases to date and can therefore tell you which of those are available right now for Upgrade purchases. I only have one in the list, but that's probably because they're still in the early stages of the program; I expect that list will grow significantly in the coming months.