The trash can icon.
Step 1: Find photo you want to delete.
Step 2: Tap it so it takes up your screen. Your options should show up. (Next pic, previous pic, trash can icon, photo #, etc.)
Step 3: Tap the trash can icon and choose "Delete Photo".
Done.
Oh, and to the previous poster, an iPod is a real mp3 player. The iPod does just fine. It's iTunes that's the problem. I have an iPod Touch 1G on 3.1.2, and while I'm disappointed in the firmware upgrade, I still like the Touch. I'm not a fan of the other iPods, though. Don't like the click wheel. The Zen is a better mp3 player, but that doesn't make the iPod Touch a bad one. It can still do things that my Zen can't. So please keep the flaming to yourself.