The Android Tools library currently contains a class that is able to load images from a network resource (specified using a URL). It handles the downloading and caching of the images, and renders them at a desired resolution. Once that has been done, a callback method is called, and the callback method can then display the updated image in the application. This class is used in many places in DHS Buzz.
Available for download is the source code to the library. Please note that in order to use this code you have to supply your own implementation of SQLiteDatabaseWrapper as well as an implementation of the method StorageHelper.getDatabase(). Finally you also have to make sure that the database tables are created by running StorageHelper.createTables(). The last part is best performed as part of your implementation of SQLiteOpenHelper.