Direct from the publishers website you can get "The PhotoShop Anthology: 100 Web Design Tips, Tricks & Techniques" for free.
Just click on the link and enter a valid email address and they will send you a download link for the full PDF version of the book in both print quality and a lower res quality.
The only difference to the print edition is that the book is linked to a competition to win a MacBook and it has a small banner across the bottom of each page.
The book is targeted at Photoshop CS2 but the introduction says it should work with all versions.
I have been subscribed to SitePoints mailing list for a few years now (and bought a number of their excellent books) and haven't had problems with spam from them - however in this instance I would suggest using a throwaway email address as there are links to third party companies that I haven't previously dealt with and the the offer is obviously linked to a marketing campaign.
Here is the full email offer I received including the accress link:
Our entire Photoshop Book is FREE to download for 14 days!
You've downloaded PDF sample chapters of SitePoint's books in the past, so I thought you'd be thrilled to discover that for the next 14 days you can download the full 278 page PDF version of "The Photoshop Anthology" (usually $29.95) for FREE!
Here's your link to snap up a free copy:
There's no catch. This is no "special offer." It's purely a FREE giveaway of this incredible book.
Grab your copy today before our servers go into meltdown!
All the best,