What to do about app that starts using excessive storage space? I have noticed that sometimes an app will start using an excessive amount of space.

For example, I've recently seen a few examples where the Amazon app was using over 350MB of storage.

One solution is to clear all the data for the app.  But then the user must reconfigure the app from scratch.

Is there any way to fix this issue without clearing all the data for the app?
One option would be to freshly install the app, set it up, then back up its settings using Titanium Backup or another similar app.  Then you can freely wipe the data when needed and quickly restore the basics.  This won't necessarily work if they significantly change how a new version of the app stores its data, of course.