Do you have a Mac or Windows? If you have Mac iPhoto is a program, but if you have Windows, you can just go and delete those pictures out of where it is syncing them, or make a separate roll where you can put the pictures you want on the iPhone.
I have a laptop with Windows XP and an unlocked iPhone and I have tried a couple different ways to delete photos without much success.
the first way is by pluging the iPhone into my computer and selecting the option to delete the photos after uploading them. I have tried this several times and every time it gets as far as two or three photos and then the iPhone reset itself.
the other method is to delete them through windows explorer. I can delete the one at a time no problem but, every time I try to do more than 3 or 4 at a time, same thing happens. the iPhone restarts itself and my photos are all still there. I'm not sure what to do but at this point over half the photos on my phone are old ones that I have already uploaded, how can I get rid of them?
I use IfunBox.exe which is much better than other apps such as iPhoneBrowser. You can add and delete via IfunBox. I have added movies, pics, files, etc. To add Files to IfunBox - Just open File Explorer (I use Total Commander on my PC) drag and drop the file into IfunBox. To Delete - Just use IfunBox, go to the file and delete. Hope this helps you and others. If you run into a problem, just let me know. kk