Here's a great summary of useful resources on mobile learning from the Software for Learning website: http://softwareforlearning.tki.org.nz/Software-in-schools/mLearning...practical ideas, research and school snapshots.
How is mobile learning working at your school?
...and here's a useful teachers' guide on mobile learning via the 21st Century Fluency Project:
Education’s Guide to Mobile Devices: Everything You Need to Know About Mobile Tech and Your Schools” (PDF).