Google's Android App Inventor is great fun to play with and I think represents a fascinating leap forward in mobile application development. It provides a whole toolbox of ready to go functionality, but sadly missing from this toolbox are facilities to interact with web sites and services (with the exception of Twitter of course). However there is one component that provides a glimmer of hope and if you want to publish data in a way that can be used by Android App Inventor developers then you can use this component with a PHP script to easily pass data to the mobile device.
Mobile broadband is becoming more popular now and many people are enjoying the convenience of being able to get broadband internet from a wide variety of locations. Both pre-pay and contract options are available on connections and the cost of using this service can be very reasonable. A lot of contracts are based on the idea of paying a certain rate for a set amount of data, for example £10 might buy you 1GB of data, but go over this allowance and the surfing could start getting a bit more expensive with each megabyte being charged separately at a high rate.