MisterMonday writes: Box.net, arguably the second most-popular online storage service, is now offering 50GB of storage space free for users who log in through their Android application until March 23. This is a lifetime upgrade, compared to the standard free 5GB for other users. Larger storage spaces are available, of course, for a monthly fee. Box.net has offered similar promotions to attract users before, including for iOS users. Unlike the iOS promotion, however, file sizes are still limited to 25 MB, whereas the iOS promotion also increased it to 100 MB.