The "OTHER" category on iphone storage is eating up the whole status bar.

After the 2.21 update my girlfriend's phone shows up as out of memory. The memory usage status bar in iTunes shows the "other" category as eating up two thirds of her storage. What can she delete to get rid of the "other" crap. She's trying to avoid restoring the phone to "new". She restored Fromm the backup and it gave her the same problems.