I have some photos from the camera roll that I want to delete permanently (meaning it won't be recoverable by anyone in the future). So do I just delete it from the camera roll and the photos will be permanently removed? And I haven't sync to itunes after I took the photos. Thanks.
Deleting the pictures from the camera roll will permanently delete the photos from your iPhone.
FYI: The camera roll photos are not included in the sync process. If you want to save photos from the camera roll to your computer they need to be imported from your iPhone. This process is explained in the user manual and in various threads on this forum.
Well, that's a little different than "permanently deleting" the photo. I don't believe the iPhone overwrites data when it is deleted. Someone with access to the phone and the right software (such as a police agency with the right warrants) would still be able to recover data from the phone until the area where the data was stored has been overwritten by other data. If I'm wrong on this I'm sure someone will come along and provide you with the correct information.
So theoretically, if I take pictures till I max out my memory then that will overwrite my old photos so even recovery programs won't be able to recover my old photos?
Those must be quite the pictures! Yes, I believe adding pictures, movies, music or whatever type of data to the phone will eventually overwrite the pictures you want to be gone.