I think there's a bit too much whitespace in there.
Also, as a general rule, don't let the browser resize images
http://www.ticklefishdesign.com/tick.../ktuk_site.gif
It looks really nasty. Shrink them and make some thumbnails using photoshop instead. For images like that, you should be using jpg not gif. Gif looks nasty and dithered because it doesn't support the same colour range as jpg.