A little heads up for developers out there looking to get into Windows Phone games, 'Sams Teach Yourself Windows Phone 7 Game Programming' has had a nice price drop on Amazon (at least in the UK) down to £17.54. The long running series of books cover many topics, and with the increasing visibility of the platform, this might be a nice bit of summertime reading to get you started.

From the bullet poin t blurb, the book covvers techniques and how to:

• Develop fast, playable Windows Phone 7 games with XNA 4.0.
• Get and manage user touch screen input.
• Draw 2D bitmapped images, and bring them to life as sprites.
• Transform sprites using rotation, scaling, and velocity calculations.
• Detect and handle collisions between game objects.
• Create surprisingly realistic animation effects.
• Master sophisticated finite state programming techniques.
• Integrate GPS Location Services into your game.
• Make the most of Windows Phone audio.
• Read, write, and save game files.
• Create your game’s Graphical User Interface (GUI).
• Implement realistic physics effects, including gravity and acceleration.
• Tweak gameplay to make your games more fun.

Pick up your copy at Amazon.