There is more fluid beauty at Liquid Sculpture, the portfolio of photographer Martin Waugh. Crisp, vivid images in a remarkably diverse array of colors and forms. Lovely and surprising.
Then there is this nice collection of waterdrops. They are hosted at JSFotografie, though there is no link to them through the main site and they don't seem to belong to the body of work featured there. I'm not sure if they're the work of the same photographer or not. Still, they are very nice.
Using x-rays rather than a camera, Judith K. McMillan captures gorgeous, ethereal images of plant specimens. The elegant black-and-white compositions are ghostly and fascinating. Don't miss.
Katinka Matson does beautiful scanner photography of flowers. These bold, wonderfully detailed images are created by arranging the subjects directly on a flatbed scanner, and the results are amazing. In addition to the images on her site, you can also browse the online exhibition FLOWERS for a guided intro to her work.
Eye of science is a stunning microphotography site with amazingly detailed, brightly colored images of the microcosmic world. There are a number of categories, including crystals, botany, bacteria and viruses, and zoology. The images are not only informative and revealing, but beautiful, and each is accompanied by a brief explanation. (Below are an owl's feather and a crystalline substance called Tetradecanol-1.)
Then there's one of my favorite photoblogs, Artsy Science, featuring great microscopic and close-up photography. The latest posted picture is an excellent example of the bright and pretty things you'll find there all the time. This shot happens to be of an Equisetum strobilus.
Sensitive Light has, among other great things, a very nice, very large gallery of colored smoke. The delicate, trailing ribbons of smoke form graceful, dazzling sculptures suspended in air. The images are so clear and sharp that some almost look computer generated.