String fileId = CloudStorage.getInstance().uploadCloudFile(mimeType, fileName);
This will block to upload the file so you might want to display an infinite progress indicator or something, once its done and the file was uploaded you can just call:
String url = CloudStorage.getInstance().getUrlForCloudFileId(fileId);
That URL will provide you with the file download and you can delete the file via deleteCloudFile(fileId). In the upcoming version we are also adding deleteAllCloudFilesForUser() and deleteAllCloudFilesBefore(timestamp, developerAccount, developerPassword) which will allow you to purge some of your quota.
You can use this for image exchange and other such tricks but one of my favorite concepts is sharing data between devices e.g. you can upload your application state as a file to the cloud and expose it via a QR code like this:
int size = Math.min(Display.getInstance().getDisplayWidth(), Display.getInstance().getDisplayHeight());
Label qrCode = new Label(new URLImage("http://chart.apis.google.com/chart?cht=qr&chs=" + size + "x" + size "&chl=" + fileId + "&chld=H|0"));
Now on the other device just scan the QR code and download the file to import the data, trivial synchronization between devices without typing a single word into the device!
The image you see on the right is a bit unrelated but you might find it interesting... A corporate account requested native Google Maps support for iOS/Android, we already have a prototype on iOS although Android is a bit more of a challenge. We hope to have something to show soon though.