Free Apress ebooks

I've just been told that Apress have started offering some of their books in pdf format, and that for a limited time they can be downloaded free of charge.

The items on offer are:
Writing Perl Modules for CPAN,
Programming VB.NET: A Guide for Experienced Programmers,
Programmers Introduction To PHP4,
Dissecting a C# Application,
COM and .NET Interoperability

Note: Source code etc can be downloaded from Apress