Free "Programming Windows Phone 7" ebook by Charles Petzold

If you are interested in learning about software development on the new Microsoft Windows Phone 7 platform grab your copy of the over 1000 pages long ebook "Programming Windows Phone 7" by Charles Petzold. Topics covered are both SilverLight and XNA programming on Microsoft Windows Phone 7. There is also source code to go along with the book ... here is the C# version of the samples and here is the VB.NET version of those same samples.