OK, I need to produce slices of photos for header backgrounds on a website. The slices need to be 100px high, but I don't mind how wide they are (as long as it's >~1800px: the pictures are the background to a header in the CSS, fixed on the right side so more photo will appear on the left as the window-width is increased). Basically, I want to be able to produce a crop of the photos where I can quickly see what is going to be output, either by masking or a preview. I would sometimes be scaling the original photo in order to fit more in the 100px height. In Photoshop you the Marquee tool can be constrained to a specific ratio or specific dimensions. However, I don't want to fix the width of the selection, just the height. I'm sure I'm missing something pretty obvious. I've got CS3 Design Premium plus most other obvious Mac software but if one of the recent spate of OS X image-editing applications has this feature built-in then I'd consider getting a licence. I want to breeze through a folder full of these images producing slices, so I don't want it to be a particularly laborious process for just one image! Thanks in advance for any help.