From the press release:
Apress L.P. is pleased to announce the creation of the Apress eBookshop. Earlier in 2005, Apress launched the "Free eBook" series. This is a continually growing collection of essential titles, including "A Programmer's Introduction to PHP 4.0," that Apress offers its readers for free. With hundreds of copies of its books being downloaded on a daily basis, Apress is seizing the opportunity by offering IT professionals worldwide a variety of ways to stay at the forefront of technology.
To access the Apress eBookshop, visit http://eBookshop.apress.com or http://www.apress.com.
As you would expect, the prices are dramatically lower for eBooks, which are delivered as PDF files. So far, I am very impressed!
Also, they have a What's New RSS feed.