How to switch pics from one iPhone to another?

I just got an iPhone 4S and I'm trying to get all my pics switched to my iPhone 4S from my old iPhone 4 is there any way to do this? I have a PC but If there's a way to switch just using my iPhones then that would be easier for me. If I could avoid paying for something or an app that would be great.

Simple, if you have both phones.
Connect and backup your old phone to iTunes. Then disconnect it.
Connect the new phone to iTunes and choose restore.
All apps, data, pics, music, and sync settings will transfer over to the new phone.
You can do this with future phone updates as well.