How to get rid of albums on iPhone?

I connected my iPhone 4s to the latest version of iTunes and synced a folder of pictures from my computer to my phone. Now on my phone I have 3 albums, Camera roll, Photo Library and "phone" last one is my synced. I just want them all in one album, but I can't delete them…

Unfortunately you can delete the camera roll album itself because all the pictures you take on your phone will be saved to that folder but you can go into that folder press edit then select the photos you want to move the move them to the album you want, do the same with the photos in the albums you want to delete then once they are all in the same album you go to the list of albums press edit then tap the red dot which will give you the option to delete,
To prevent this from happening again create a folder in your documents of all the pictures you have on your phone then go to iTunes with you phone connected, go into the pictures tab and select that folder now unless you add more images to that folder in the future if you accidentally sync that folder nothing will change xxx
Hope this helps