If your iPhone or iPod is being plagued by the "Other Files" bloat, this is one way you can fix it. I recomend that if you're not an advanced user, you don't try this and you proceed at your own risk. You can mess up your phone, if you do something wrong... or maybe if you even follow these directions to the letter. Don't try this.

I had a problem where my iPhone had 3.2gb of "Other Files" and the recomended procedure to fix this problem was to restore the phone, over writing everything. Yes, this might fix the problem, but it's over kill. Why not just find the files that are in question and delete them? That's what I did, and it worked.

To begin
1. Connect your iDevice to your computer.
2. Use a tool that will allow you to easily navigate your phone's directories, such as i-FunBox, HERE
3. Navigate to /private/var/mobile/media/iTunes_Control/Music
4. The files contained in these folders are your music and movies. Deleting them should clean out the files listed as "Other" but it will also delete all your music and movies. If you have a lot of space showing up as "Other" this is probably where it's being wasted at.

Don't feel tempted to delete the directories. If you do, It'll fail to sync correctly. You must keep the folder structure and permissions. If you've done this, and you're getting an error -54:

Error code 54 indicates "Software lock on file; Not a subscriber"

It's because you've changed the permissions on the files in the Media folder.

For the Media folder, the owner is mobile and the group mobile. All files below it should have the same thing. You can set them by using  putty. Navigate to /private/var/mobile/media/iTunes_Control/Music and type chown -R mobile ./F*