How to get unwanted photos off the iPhone 4?

Somehow, when I synced my phone to my computer, the photos on my computer got onto my phone. It's taking up a lot of space and I CAN'T DELETE THEM WHATSOEVER! Is there a way to un-sync them? I need help!

There always a way to delete photos

Did you try to swipe the album title and click the delete symbol?

also if its syncing pics it probably means the you have it "checked' to sync them in iTunes.
Once you connect your device to iTunes, there's a section that pops up where you can check and uncheck everything that goes in.(songs, videos, photos etc.) Look for the tab that controls photos. Uncheck that and sync your device again.