Scholastic has some some nice ideas for using mobile devices in class.
This is a great list of apps to use in the classroom.
Portable Apps has a great collection of applications that can run directly from memory sticks.
Ipadio is a site that lets you create your own audio/phone blog (phlog). You can call into the site or download an app on your mobile device devices that allows you to post audio blogs on the move. you can also add pictures, geolocation and embed the pholog into a website of blog if you like.
Woices is a great app for iphone, android and blackberry that lets you create, share and find geolocated audio recordings. Great for audio guides, treasure hunts and situated learning.
(Featured Image adapted from: CÃ©sar Poyatos)