TimeCapsule is a 3rd party application for iPhone and iPod Touch. It can keep multiple states of a particular program by saving its preferences/settings/databases. These states are restorable. Currently, the TimeCapsule only supports backup/restore of the following apps:

AddressBook’s contacts
Call History
Installer’s sources
Map’s bookmarks & history
Map’s caches (not tested)
Notes
Safari’s bookmarks & history
YouTube Video Cache
SMS
Transit’s Preferences
Stocks
VoiceMail
Weather
WorldClock

http://databinge.com/blog/