Technology Integration Matrix with video examples for every topic and level of integration. Not iPad specific, but a great place to start when integrating technology.
PE teachers are often left out when it comes to technology integration. This is a great article full of suggested apps and links for integrating an iPad into a PE curriculum.
disclosure: I am the Director of Edcuational Technology at Mulgrave. This fall Mulgrave School in Vancouver, Canada, handed iPads to all the Grade 3 classes. Three weeks into the academic program and lead teachers on the project, Melanie Cannon and Shauna Ullman throw down one of the best uses of the iPad I've seen yet.
This free eBook is available for download and provides a great interactive resources. Each section ties into some aspect of Bloom's Taxonomy and provides additional information to support iPad integration into the curriculum.
Though an older post, this is still a good starting point for integrating QR codes into the classroom. The Mobile Native is a great blog for integrating mobile devices and focuses on younger students.
This product from the School Improvement Network facilitates administrative classroom walkthroughs in that it leverages the camera capabilities of the iPad/iPhone/iPod Touch and integrates it with assessment tools designed to give teachers constructive feedback.