mills:

Most of the people who see this site use Firefox, and thus see a hideous border around the Flickr photos to the right. I’ve spent a lot of time trying to get that border to go away while retaining that precise arrangement of tiles, which I like, to no avail. This bothers me, so I’m (a) venting and (b) apologizing to the Firefox folks.

Mills, try sticking this in your CSS:

.flickrimages img { border: none; }

I think that should fix you up, unless I’m not taking your meaning re the precise arrangement correctly.