Downloaded photos off my computer?

Apple iPhone - Accidentally downloaded all the photos off my computer

When I was syncing my IPhone 4 I saw I could import photos. Silly me, I thought I was importing the iphone photos from the phone to the computer (HP pavilion XP), but instead, I ended up with all the photos from my computer onto my phone. That's not a big problem because I have 32g and not that much else on it taking up space right now.

However, a lot of the photos are duplicates or simply bad photos that I'd just as soon delete off my phone -- but not off the computer. I don't see any way to do that. Suggestions?

iphone photography
Two options:

Segregate the photos you want to copy to the iPhone from those you don't and point iTunes to use only the folder with the photos you do,

or use Photoshop Elements' Organizer to create albums and set iTunes to use Photoshop Elements instead of a folder location.

-----
You're lucky. I've got over 36 GB of images on my desktop computer (including various types of duplicates).