One of my sites is an art gallery, and the artist doesn't want them cropped . So I've got vertically oriented thumbnails and horizontal thumbnails somehow throwing each other off and creating a bunch of unnecessary and distracting whitespace. Any idea how to fix this?

Here's the site.

Make each box a square of the right size (width of the landscapes) and center them either vertically or horizontally. Centering can be tricky in CSS, but not terrible. Alternatively, you could use the Zenphoto getSize... functions to apply different styles to each.

This is an old post, but the comment of trisweb made me think about centering the thumbs again...

Suddenly I'm getting annoyed by the fact that the thumbs on my site (not squared) are centered horizontally but not vertically. Could this 'getSize...' function trisweb mentioned be a solution for this?

It's tricky. I've seen it work on other sites, but in the source of those pages each <img> 'fysically' gets a width and height and after that the vertical centering is done with css. Without those values it's impossible to achieve the vertical centering because there is no reference, am I right?