How to transfer pictures from iPhone to flash drive
Put the pics onto your computer then onto your flash drive.
Put the pictures from iPhone from 'iPhoto' > copy to your computer > copy to your flash drive. Done :)
First you will have to sync your iPhone to your computer so that the photos are copied onto your computer. Then you insert the flash drive into the computer and drag the photos you want to transfer to the drive. See http://www.ehow.com/how_7337929_transfer-iphone-photos-thumb-drives.html for more instructions.
Well, you can use Amacsoft iPhone transfer to move iPhone photos to computer firstly, then just need copy the transferred photos to flash drive. This guide would would help you know how to move photos from iPhone to Mac/PC: http://is.gd/gCIuTt