In iOS4.3.3 update, Apple fixed the background tracking "bug", it's good. But..., do you want this Feature back?
AutoDiary fulfill your requirement. Of course, it's fully under your control and protected by password now. With this tool you can check where you were, what you were doing (if recorded) in particular time.
Besides, this app is multi-usage, you can use it:
-As travel journal.
-Like an e-diary, which can write...